Male Muscle System - Overview

<body>  <title>Handbook - Male Muscle System - Overview</title> <META name="Description" content="WormAtlas: A database of behavioral and structural anatomy of Caenorhabditis elegans."> <META name="KeyWords" content="Caenorhabditis, elegans, anatomy, hermaphrodite, worm, nematode">  <META http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <META name="Copyright" content="www.wormatlas.org"> <link rel="StyleSheet" href="../../css/common-style.css" type="text/css"> <link rel="StyleSheet" href="../../css/gray.css" type="text/css"> <link rel="StyleSheet" href="../../css/gray-menu.css" type="text/css"> <script language="JavaScript" type="text/javascript" src="../../css/css.js"></script> <script language="JavaScript" type="text/javascript" src="../../javascripts.js"></script> <script language="JavaScript" type="text/javascript" src="../../pop-closeup.js"></script> <style type="text/css">  </style> </head> <BODY BGCOLOR="#FFFFFF" TEXT="#000000">  <table cellpadding="0" cellspacing="0" border="0" width="100%"> <tr><td align="center" valign="top"> <a name="top"></a>  <table cellpadding="0" cellspacing="0" border="2" width="100%"><tr> <td background="../../art1/oldheadercolor.jpg" class="pictbackground"><img src="../../ART1/headerA2b.jpg" width="829" height="86" border="0" usemap="#Map2"> </td> </tr><tr class="printhide"><td class=""> </td></tr></table>  <script language="JavaScript" type="text/javascript" src="menu.js"></script>  <table cellpadding="0" cellspacing="0" border="0" width="100%"> <tr> <td width="1051" align="left" valign="top" class="shadow-horizontal"> <br> <br>  <table cellpadding="5" cellspacing="0" border="0"> <tr> <td align="left" valign="top" class="just">  <span class="title"><span class="style5"><a name="Musclesystemofthemaleoverview" id="Musclesystemofthemaleoverview"></a>MUSCLE SYSTEM OF THE MALE </span>- OVERVIEW </span>  <center> <TABLE align="left" cellpadding="0" cellspacing="0" class="gallerytext"> <tr> <td width="1169" align="left" class="style1"> <span class="subtitle"> <a name="Generalinformation1" id="Generalinformation1"></a></span><span class="style10"><br> 1 General Information <strong> </strong></span> <p>The muscle system of the male differs from that of the hermaphrodite primarily in its complement of sex muscles, derived from the <a href="../../images/Mlineage.jpg" target="_blank">M lineage</a>. The adult male has 41 M-derived sex muscles consisting of 7 morphologically distinct types. None of these muscles are present in the hermaphrodite and so they are male-specific muscles. These muscles are distributed through the posterior half of the animal and function in various aspects of male mating behavior or copulation (<a href="#MaleMusFIG1">MaleMusFIG 1</a>, <a href="#MaleMusFIG2">MaleMusFIG 2 </a>and <a href="#MaleMusMOVIE1">MaleMusMOVIE 1</a>; <a href="#Sulston1977">Sulston and Horvitz, 1977</a>;<a href="#Sulston1980"> Sulston et al., 1980</a>). Indeed, several sex muscles are directly associated with structures and tissues of the male copulatory apparatus such as the spicules and the gubernaculum (see also <a href="../musclemale/Musmaleframeset.html" target="_blank">Male-specific muscles</a>). Surprisingly, males in which M has been ablated can execute most of the initial steps of mating (backing, turning, vulval location; <a href="http://elegans.swmed.edu/wli/%5Bwbg7.2p22%5D/?%5Cb%5Bs%DF%5D%5Bc%E7%5Dr%5Be%E9%E8%EA%EB%5Dw%5Cb%3B%5Cb%5Bs%DF%5D%5Bu%FA%F9%FB%FC%5Dl%5Bs%DF%5D%5Bt%FE%5D%5Bo%BA%F3%F2%F4%F6%F5%F8%5D%5Bn%F1%5D%5Cb" target="_blank">Sulston, J.E., WBG 7(2):22</a>), although their execution is significantly poorer than in wild type (see <a href="#Loer1993">Loer and Kenyon, 1993</a>). The spicules in such ablated animals do not function. Thus some male-specific muscles are essential for mating (e.g. the spicule muscles) while others appear to enhance the animal's ability adopt certain postures required during mating.</p> <div align="center"><a href="../../movies/Mating.mp4"><img src="../../movies/Mating.jpg" alt="MaleMusFIG 1 The adult male sex muscles" name="MaleMusFIG1" width="633" height="288" border="0" align="middle" class="Galborder" id="MaleMusFIG1"></a><a name="MaleMusMOVIE1" id="MaleMusMOVIE1"></a></div> <span class="picturetitle"> MaleMusMOVIE 1: Light microscopy image of a male copulating with a hermaphrodite. </span><span class="style2">Click on picture to watch movie. </span> <p>In addition to the sex muscles, a few embryonically-derived muscles that are present in both males and hermaphrodites (sphincter, anal depressor and body wall muscles) express different characteristics in the male and are employed in mating behavior or copulation (<a href="#MaleMusFIG1">MaleMusFIG 1B</a>, underlined labels and <a href="#MaleMusMOVIE1">MaleMusMOVIE 1</a>; <a href="#Sulston1977">Sulston and Horvitz, 1977</a>; <a href="#Sulston1980">Sulston et al., 1980</a><a href="http://www.wormatlas.org/ver1/Sulston%20postembmale_1980/toc.html" target="_blank"></a>;<a href="#Sulston1983"> Sulston et al., 1983</a>). </p> <div align="center"><img src="images/MaleMusFIG1.jpg" alt="MaleMusFIG 1 The adult male sex muscles" name="MaleMusFIG1" width="743" height="708" border="0" align="middle" class="Galborder" id="MaleMusFIG1"><a name="MaleMusFIG1" id="MaleMusFIG1"></a></div> <span class="picturetitle"> MaleMusFIG 1: The adult male sex muscles.</span><span class="style2"> <strong>A. </strong><span class="style18"> Epifluorescent images from transgenic animal expressing the<em> unc-27 ::GFP</em> reporter gene (Troponinl), left lateral oblique view. (Strain source: L. Jia and S.W. Emmons.)</span> <strong>B. </strong>Illustrations highlighting area boxed in <strong>A</strong>, left lateral view. Sexually dimorphic areas are underlined. <strong>Lateral </strong>(dBWM and vBWM) Dorsal and ventral body wall muscle; (aolL and polL) anterior and posterior longitudinal, left; (cdlL) caudal outer longitudinal, left. <strong> Medial-lateral </strong>(dglL) Diagonal muscles, left; (grtL) gubernacular retractor, left; (aobL and pobL) anterior and posterior oblique, left. <strong>Medial</strong> (v/dsrL) Ventral and dorsal spicule retractors, left; (v/dspL) ventral and dorsal spicule protractors; (sph) sphincter; (ailL and pilL) anterior and posterior inner longitudinal; (gecL) gubernacular erector, left; (adp) anal depressor.</span> <div align="center"><br> <img src="images/MaleMusFIG2.jpg" alt="MaleMusFIG 2 Male mating behavior" name="MaleMusFIG2" width="750" height="721" border="0" align="middle" class="Galborder" id="MaleMusFIG2"><a name="MaleMusFIG2" id="MaleMusFIG2"></a></div> <span class="picturetitle"> MaleMusFIG 2: Male mating behavior. </span><span class="style2">Steps in mating featuring participating muscle groups. (Based on <a href="#Loer1993">Loer and Kenyon, 1993</a>; <a href="#Liu1995">Liu and Sternberg, 1995</a>; <a href="#Barr1999">Barr and Sternberg, 1999</a>; <a href="#Garcia2001">Garcia et al., 2001</a>.)</span> <p>With the exception of the longitudinal muscles, the (M-derived) sex muscles of the male generally conform to the non-striated class of muscle types (see <a href="../../hermaphrodite/muscleintro/MusIntroframeset.html" target="_blank">Muscle System - Introduction</a> for a description of muscle types and <a href="../../hermaphrodite/musclenonstriated/MusNonstriframeset.html" target="_blank">Muscle System - Nonstriated Muscle</a> for hermaphrodite nonstriated muscles. In contrast to striated muscles (e.g. body wall muscles), non-striated muscles contain a single or only a few sarcomeres (contractile units) and attach to cuticle only at their ends (for organization of attachment sites see <a href="../../hermaphrodite/cuticle/Images/cutfig10leg.htm" target="_blank">CutFIG 10</a>, <a href="../../hermaphrodite/cuticle/Cutframeset.html" target="_blank">The Cuticle</a>; <a href="../../hermaphrodite/musclesomatic/Images/musfig11leg.htm" target="_blank">MusFIG 11</a> and <a href="../../hermaphrodite/musclesomatic/MusSomaticframeset.htm" target="_blank">Somatic Muscle</a>). The cuticle acts as an exoskeleton for muscle contraction to work against. In the male the cuticle may be body wall cuticle, as in the hermaphrodite, or a male-specific cuticle such as the spicules or the gubernaculum (<a href="#MaleMusTABLE1">MaleMusTABLE 1</a>). Certain subsets of muscles in the male are also connected to each other via attachment plaques (<a href="#MaleMusTABLE1">MaleMusTABLE 1</a>; denoted by yellow arrows in chapter figures). These muscle::muscle connections share some molecules in common with cuticle::muscle connections (see <a href="../../hermaphrodite/musclesomatic/MusSomaticframeset.htm" target="_blank">Muscle System - Somatic Muscle</a>). While the bulk of contractile force is likely to be transmitted to cuticle, muscle::muscle connections may transmit some pulling force between interconnected muscles, enhancing their ability to function as a unit (for example the spicule protractors and anal depressor muscles). Also like muscles elsewhere in the body, the male sex muscles have muscle arms and these are often the sites for innervation. However, the arms can be short and in some cases synapses are made in the absence of arms, directly on to the muscle sarcomere region (e.g. spicule protractors, <a href="../musclemale/Musmaleframeset.html" target="_blank">Male-specific Muscles</a>). </p> <div align="center"><img src="images/MaleMusTABLE1.jpg" alt="MaleMusTABLE 1 Summary of muscle attributes" name="MaleMusTABLE1" width="905" height="759" border="0" align="middle" class="Galborder" id="MaleMusTABLE1"><a name="MaleMusTABLE1" id="MaleMusTABLE1"></a></div> <span class="picturetitle"> MaleMusTABLE 1: Summary of muscle attributes. </span><span class="style2">(nd) Not determined. (Source: <a href="http://wormwiring.org/male/male.php" target="_blank">The Male Wiring Project</a>; Sulston et al., unpublished). </span> <hr class="page-splits"> <span class="subtitle"><a name="Developmentofthemalemusclesystem2" id="Developmentofthemalemusclesystem2"></a></span><span class="style10"><br> 2 Development of the Male Muscle System </span> <p>Sexual specialization of the male muscle system beings in L2 and continues through to the final (L4-adult) molt. Sex-specific differences derive from two sources (1) the M-lineage (<a href="#MaleMusFIG3">MaleMusFIG 3</a>), which generates 41 sex muscles not present in hermaphrodites and (2) male-specific modification of certain juvenile muscles that are common to both sexes.<br> <strong><a name="Malespecificmuscles21" id="Malespecificmuscles21"></a><span class="style13"><br> 2.1 Male-specific (M-derived) Muscles </span></strong> <p>During late L2 the M lineage of the male executes a different lineage from that in the hermaphrodite and produces 3 bilateral pairs of Sex Myoblasts (SM1-3L/R) (<a href="#MaleMusFIG3">MaleMusFIG 3</a> and <a href="#MaleMusFIG4">4</a>). As in the hermaphrodite, SMs migrate from their birth position but move in the opposite direction, towards the tail instead of anteriorly (<a href="#Sulston1977">Sulston and Horvitz, 1977</a>;<a href="#Sulston1980"> Sulston et al., 1980</a><a href="http://www.wormatlas.org/ver1/Sulston%20postembmale_1980/toc.html" target="_blank"></a>; <a href="#Branda2000">Branda and Stern, 2000</a>). During L3 the SMs divide 2 or 3 times to generate 41 male-specific muscles (the sex muscles; <a href="#MaleMusFIG3">MaleMusFIG 3</a>, <a href="#MaleMusFIG5">5A-D</a>). SM3L(left) and SM3R(right) have identical lineages, while the SM1left/right homologs as well as those of SM2 produce non-identical lineages (summarized in <a href="#MaleMusFIG4">MaleMusFIG 4</a>). Lineage execution is accompanied by a number of short-range migrations (see <a href="#Sulston1980">Sulston et al., 1980</a>, <a href="http://www.wormatlas.org/ver1/Sulston%20postembmale_1980/results.html#fig27" target="_blank">Fig 27</a>, for details). </p> <div align="center"><img src="images/MaleMusFIG3.jpg" alt="MaleMusFIG 3 The M lineage" name="MaleMusFIG3" width="795" height="288" border="0" align="middle" class="Galborder" id="MaleMusFIG3"><a name="MaleMusFIG3" id="MaleMusFIG3"></a> </div> <span class="picturetitle"> MaleMusFIG 3: The M lineage. </span><span class="style2">(L) Left; (R) right; (ail and pil) anterior and posterior inner longitudinal; (aob and pob) anterior and posterior oblique; (aol and pol) anterior and posterior longitudinal; (cc) coelomocyte; (cdl) caudal outer longitudinal; (dgl) diagonal; (gec) gubernacular erector; (grt) gubernacular retractor; (vsr and dsr) ventral and dorsal spicule retractors; (vsp and dsp) ventral and spicule protractors. </span> <div align="center"> <hr class="page-splits"> <img src="images/MaleMusFIG4.jpg" alt="MaleMusFIG 4 Muscles produced by the SMs" name="MaleMusFIG4" width="540" height="334" border="0" align="middle" class="Galborder" id="MaleMusFIG4"><a name="MaleMusFIG4" id="MaleMusFIG4"></a> </div> <span class="picturetitle"> MaleMusFIG 4: Muscles produced by the SMs. </span><span class="style2">DIC/ epifluorescent image from transgenic L3 animal expressing the<em> hlh-8 ::GFP</em> reporter gene (transcription factor). (Strain source: B.D. Harfe, M. Krause and A. Fire.)</span> <hr class="page-splits"></td> </tr> <tr> <td align="left" background="#Chinsang2000" class="style1"> <div align="center"><img src="images/MaleMusFIG5.jpg" alt="MaleMusFIG 5 Division of the SMs to produce the sex muscles" name="MaleMusFIG5" width="800" height="456" border="0" align="middle" class="Galborder" id="MaleMusFIG5"><a name="MaleMusFIG5" id="MaleMusFIG5"></a><span class="picturename"> </span></div> <span class="picturetitle"> MaleMusFIG 5: Division of the SMs to produce the sex muscles. </span><span class="style2"> Epifluorescent images from transgenic animals expressing the<em> hlh-8 ::GFP</em> reporter gene (transcription factor). (Strain source: B.D. Harfe, M. Krause and A. Fire.) <strong>A. </strong> L3 animal at approximately 27 hours, lateral view, right side. <strong>B.</strong> L3 animal at approximately 30 hours, lateral view, right side. <strong>C. </strong> L4 animal at approximately 35 hours, lateral view, right side. Terminal cells are born (SM.xx/xxx). Several migrate to reach final position (aob,pob, grt, gec).<strong> D.</strong> L4 animal during morphogenesis at approximately 42 hours, lateral view, left side. Terminal cells in final position. (Fewer cells express reporter at this stage as HLH-8::GFP signal diminishes in maturing terminal cells.)</span><br> <strong><a name="Sexuallydimorphicmuscles22" id="Sexuallydimorphicmuscles22"></a><span class="style13"><br> 2.2 Sexually Dimorphic Muscles </span></strong> <p>Some tail muscles that are present in larvae of both sexes become modified in the male late in development to function in mating behavior or copulation. These alterations can be subtle, such as the establishment of connections between non-sex-specific muscles and male-specific muscles or neurons. For example, dorsal body wall muscles, present in both sexes, can be considered sexually dimorphic because they establish gap junctions with spicule retractor muscles in the male (<a href="../musclemale/Musmaleframeset.html" target="_blank">Male-specific Muscles</a>; <a href="../musclemale/mainframe.htm#MaleMusFIG25" target="_blank">MaleMusFIG25 C</a>). Other modifications are more striking, for example, the anal depressor (adp) and the sphincter (sph) undergo extensive morphological and functional changes in the male but not in the hermaphrodite (<a href="#Sulston1980">Sulston et al., 1980</a>). </p> <p>The male anal depressor (adp): In both male and hermaphrodite larvae the adp is an H-shaped cell connecting the dorsal body wall to the roof of the rectum (<a href="#MaleMusFIG6">MaleMusFIG 6</a>). Muscle myofilaments run dorsoventrally (D/V) and their contraction lifts the roof of the anus to allow defecation (<a href="#MaleMusFIG7">MaleMusFIG 7</a>). During male L4 lethargus, the adp substantially changes its shape and its contacts. The cell tilts forwards slightly but does not completely lose its contact with the dorsal roof (<a href="#MaleMusFIG6">MaleMusFIG 6</a>). Ventrally, the anterior edges of the cell grow forward so that they meet the dorsal spicule protractor muscles and form attachments with these cells (described in Male-specific Muscles). The myofilaments within the muscle reorient so that they now run anteroposteriorly (A/P) (<a href="#MaleMusFIG8">MaleMusFIG 8</a>), the same direction as the spicule protractor (<a href="#Sulston1977">Sulston and Horvitz, 1977</a>;<a href="http://www.wormatlas.org/ver1/Sulston%20postembmale_1980/toc.html" target="_blank"> </a><a href="#Sulston1980">Sulston et al., 1980</a>). Thus the adp becomes an extension of the dorsal spicule protractors. </p> <div align="center"> <img src="images/MaleMusFIG6.jpg" alt="MaleMusFIG 6 The male anal depressor" name="MaleMusFIG6" width="800" height="244" border="0" align="middle" class="Galborder" id="MaleMusFIG6"><a name="MaleMusFIG6" id="MaleMusFIG6"></a> </div> <span class="picturetitle"> MaleMusFIG 6: The male anal depressor. </span><span class="style2">Diagram showing the H-shaped anal depressor cell in larval and adult animals. </span> <hr class="page-splits"> <div align="center"><img src="images/MaleMusFIG7.jpg" alt="MaleMusFIG 7 Hermaphrodite anal depressor muscle" name="MaleMusFIG7" width="809" height="478" border="0" align="middle" class="Galborder" id="MaleMusFIG7"><a name="MaleMusFIG7" id="MaleMusFIG7"></a> </div> <span class="picturetitle"> MaleMusFIG 7: Hermaphrodite anal depressor muscle. </span><span class="style2"><strong>A.</strong> Electron micrograph featuring the anal depressor (adp), transverse view. (Image source: N2 [Hall] 550-52.) <strong>B. </strong> Detailed view of boxed region in <strong>A</strong>.(Bl) Basal lamina.</span> <hr class="page-splits"> <div align="center"><img src="images/MaleMusFIG8.jpg" alt="MaleMusFIG 8 Male anal depressor muscle" name="MaleMusFIG8" width="746" height="480" border="0" align="middle" class="Galborder" id="MaleMusFIG8"><a name="MaleMusFIG8" id="MaleMusFIG8"></a> </div> <span class="picturetitle"> MaleMusFIG 8: Male anal depressor muscle.</span><span class="style2"> <strong> A.</strong> Electron micrograph featuring the anal depressor (adp), transverse view. (N) nucleus. (Image source: N2Y [MRC] 32.) <strong>B. </strong> Detailed view of boxed region in <strong>A.</strong> (Bl) Basal lamina.</span> <p>The male sphincter (sph): Late in male development the sphincter is functionally and morphologically altered to compensate for a newly formed connection between the alimentary and reproductive tracts <a href="#MaleMusFIG6">(MaleMusFIG 6</a>; <a href="#Sulston1980">Sulston et al., 1980</a>). The muscle becomes enlarged (hypertrophied) and sends an extension dorsally which attaches to the body wall roof. Intrinsic activity of the muscle and its response to <a href="http://www.wormbook.org/chapters/www_gaba/gaba.html" target="_blank">GABA</a>, which regulates defecation, are also altered (<a href="#Reiner1995" target="_blank">Reiner and Thomas, 1995</a>; see <a href="../musclemale/Musmaleframeset.html" target="_blank">Male-specific Muscles</a>). </p> <hr class="page-splits"> <span class="subtitle"><a name="Diagonalmuscles3" id="Diagonalmuscles3"></a></span><span class="style10"><br> 3 Diagonal Muscles </span> <p>The adult male has 15 diagonal muscles (dgl's) organized in a herring-bone-like fashion along either side of the ventral midline; 8 muscles on the right side (dglR), 7 on the left (dglL) (<a href="#MaleMusFIG9">MaleMusFIG 9</a> and <a href="#MaleMusFIG10">10A</a>;<a href="#Sulston1980"> Sulston et al., 1980</a>). <strong><br> </strong></p> <div align="center"><img src="images/MaleMusFIG9.jpg" alt="MaleMusFIG 9 Diagonal muscles" name="MaleMusFIG9" width="747" height="173" border="0" align="middle" usemap="#MaleIntroFIG6Map" class="Galborder" id="MaleMusFIG9"><a name="MaleMusFIG9" id="MaleMusFIG9"></a> <span class="picturename"> </span></div> <span class="picturetitle"> MaleMusFIG 9: Diagonal muscles<em>. </em></span><span class="style2">Adult male, left lateral view. </span> <hr class="page-splits"></td> <tr> <td align="left" background="#Chinsang2000" class="style1"><div align="center"><img src="images/MaleMusFIG10.jpg" alt="MaleMusFIG 10 Epifluorescent views of the diagonal muscles" name="MaleMusFIG10" width="800" height="186" border="0" align="middle" class="Galborder" id="MaleMusFIG10"> <a name="MaleMusFIG10" id="MaleMusFIG10"></a></div> <span class="picturetitle">MaleMusFIG 10: Epifluorescent views of the diagonal muscles. </span><span class="style2">Epifluorescent images from transgenic animals expressing the<em> unc-27 </em> reporter gene (Troponinl, sarcomere thin filaments). (Strain source: L. Jia and S.W. Emmons.) <strong>A.</strong> Ventral view. <strong>B.</strong> Left, lateral view. </span> <p>Viewed by polarized light or with muscle myofilament markers, the dgl's appear to contain 3 sarcomeres (<a href="#MaleMusFIG10">MaleMusFIG 10B</a>; <a href="#Waterston1988" target="_blank">Waterston, 1988</a>). However, the myofilament banding patterning observed in electron micrographs suggests possibly fewer. Along their dorsal edges, the muscles attach to the body wall at the lateral seam and along their ventral edge near the ventral midline (<a href="#MaleMusFIG11">MaleMusFIG 11</a> and <a href="#MaleMusFIG12B">12B</a>). The attachment points are localized at the ends of the muscle cells as half I bands ending in hemidesmosomes (Hd) and connect the myofilaments to basal lamina (Bl). The basal lamina is connected to Hds in the hyp and the hyp in turn to cuticle (<em>red arrows</em>, <a href="#MaleMusFIG11">MaleMusFIG 11A</a>, <a href="#MaleMusFIG12A">12A</a> and <a href="#MaleMusFIG12B">12B</a>; see <a href="../../hermaphrodite/musclesomatic/MusSomaticframeset.htm" target="_blank">Muscle System - Somatic Muscle</a> for a detailed description of such structures). Diagonal muscles are also connected to other muscles, namely the inner longitudinal muscles (ailL/R, pilL/R). The muscles are joined via attachment plaques (muscle::muscle attachment complexes - <em>yellow arrows</em> in <a href="#MaleMusFIG17B">MaleMusFIG 17B</a>, for attachment plaque description see <a href="../../hermaphrodite/musclesomatic/mainframe.htm#Attachmentplaques22" target="_blank">Muscle System - Somatic Muscle</a>). </p> <div align="center"><img src="images/MaleMusFIG11.jpg" alt="MaleMusFIG 11 Diagonal muscle attachment site" name="MaleMusFIG11" width="698" height="486" border="0" align="middle" class="Galborder" id="MaleMusFIG11"> <a name="MaleMusFIG11" id="MaleMusFIG11"></a></div> <span class="picturetitle">MaleMusFIG 11: Diagonal muscle attachment sites. </span><span class="style2"><strong>A.</strong> Illustration of cuticle to muscle attachment regions, transverse view. Basal laminae not shown. <strong>B.</strong> Nomarski DIC, left lateral view. <strong>C.</strong> Epifluorescent images from transgenic animals expressing the<em> egl-15::GFP</em> reporter gene (FGF receptor). (Strain source: C. Branda and M.J. Stern.)</span> <hr class="page-splits"> <div align="center"><img src="images/MaleMusFIG12A.jpg" alt="MaleMusFIG 12A Ultrastructure of the diagonal muscles" name="MaleMusFIG12A" width="500" height="644" border="0" align="middle" class="Galborder" id="MaleMusFIG12A"><a name="MaleMusFIG12A" id="MaleMusFIG12A"></a></div> <span class="picturetitle">MaleMusFIG 12A: Ultrastructure of the diagonal muscles. </span><span class="style2">Low-power TEM showing the relationship of the diagonal muscle with the seam, transverse section. (PAG) Pre-anal ganglion. (Image source: N2Y [MRC] 579-20.)</span> <div align="center"><br> <img src="images/MaleMusFIG12B.jpg" alt="MaleMusFIG 12B Ultrastructure of the adult diagonal muscle" name="MaleMusFIG12B" width="527" height="632" border="0" align="middle" class="Galborder" id="MaleMusFIG12B"><a name="MaleMusFIG12B" id="MaleMusFIG12B"></a> </div> <span class="picturetitle">MaleMusFIG 12B: Ultrastructure of the adult diagonal muscle. </span><span class="style2">Higher magnification TEM of region highlighted by white box in <strong>12A</strong> featuring diagonal muscle with actin and myosin filaments, transverse view. Inset shows cuticle to muscle attachment sites.(<em>Red arrows</em>) Hemidesmosomes; (Bl) basal lamina; (SET) set cell. (Image source: N2Y [MRC] 550-4.) </span> <p>During mating when males reach the end of the hermaphrodite they execute a turn to flip to the other side (<a href="#MaleMusFIG13">MaleMusFIG 13B</a>; <a href="#MaleMusMOVIE1">MaleMusMOVIE 1</a>). This turn requires ventral curling of the tail facilitated by contraction of diagonal and other tail muscles. The diagonal muscles are innervated by the male-specific <a href="../../neurons/Individual Neurons/CPframeset.html" target="_blank">CP</a> motor neurons of the ventral cord (<a href="#White1988">White, 1988</a>). These neurons are required for precise execution of the turn (<a href="#Loer1993">Loer and Kenyon, 1993</a>). <a href="http://www.wormbook.org/chapters/www_monoamines/monoamines.html#sec5" target="_blank">Serotonin</a> (5HT) produced by the <a href="../../neurons/Individual Neurons/CPframeset.html" target="_blank">CP</a> neurons may be responsible for stimulating diagonal muscle contraction during turning as exposure of males to exogenous serotonin can induce ventral tail curling (<a href="#MaleMusFIG13">MaleMusFIG 13A</a>).</p> <div align="center"><img src="images/MaleMusFIG13.jpg" alt="MaleMusFIG 13 Male turning behavior" name="MaleMusFIG13" width="744" height="319" border="0" align="middle" class="Galborder" id="MaleMusFIG13"><a name="MaleMusFIG13" id="MaleMusFIG13"></a><span class="picturename"> </span></div> <span class="picturetitle">MaleMusFIG 13: Male turning behavior. </span><span class="style2"><strong>A.</strong> Exposure of males to exogenous serotonin (5HT) induces ventral tail curling. <strong>B. </strong>Ventral curling of male tail when the male reaches the end of the hermaphrodite body during mating. </span> <hr class="page-splits"> <span class="subtitle"><a name="Longitudinalmuscles4" id="Longitudinalmuscles4"></a></span><span class="style10"><br> 4 Longitudinal Muscles </span> <p>Three sets of longitudinal muscles are generated by the M lineage and contribute to the body wall musculature of the male (<a href="#Sulston1980">Sulston et al., 1980</a>; <a href="#MaleMusFIG14">MaleMusFIG 14</a> and <a href="#MaleMusFIG915">15</a>): (1) the anterior (aolL/R) and posterior (polL/R) OUTER longitudinal muscles, positioned just below the seam (<a href="#MaleMusFIG16">MaleMusFIG 16</a>,<a href="#MaleMusFIG18">18A</a> and <a href="#MaleMusFIG19">19A</a>); (2) the caudal OUTER longitudinal muscles (cdlL/R), which replace pol(L/R) in the tail (<a href="#MaleMusFIG19">MaleMusFIG 19A</a>); (3) the anterior (ailL/R) and posterior (pilL/R) INNER longitudinal muscles, positioned on either side of the ventral midline (<a href="#MaleMusFIG16">MaleMusFIG 16</a> and <a href="#MaleMusFIG19">19A</a>). </p> <div align="center"><img src="images/MaleMusFIG14.jpg" alt="MaleMusFIG 14 Longitudinal muscles" name="MaleMusFIG14" width="747" height="208" border="0" align="middle" class="Galborder" id="MaleMusFIG14"><a name="MaleMusFIG14" id="MaleMusFIG14"></a> </div> <span class="picturetitle">MaleMusFIG 14: Longitudinal muscles. </span><span class="style2">Illustration of adult male longitudinal muscles, left lateral side.</span> <hr class="page-splits"> <div align="center"><img src="images/MaleMusFIG15.jpg" alt="MaleMusFIG 15 Relationship between longitudinal and body wall muscles" name="MaleMusFIG15" width="675" height="273" border="0" align="middle" class="Galborder" id="MaleMusFIG15"><a name="MaleMusFIG915" id="MaleMusFIG915"></a> </div> <span class="picturetitle">MaleMusFIG 15: Relationship between longitudinal and body wall muscles. </span><span class="style2">Diagram of physical and lineal relationship between longitudinal muscles and ventral body wall muscles (vBWM), right side. BWM are derived from MS. (Based on <a href="#Sulston1980">Sulston et al., 1980</a>.)</span> <p>In contrast to other sex muscles of the male which are non-striated, the longitudinal muscles, particularly ail(L/R), pil(L/R) and cdl(L/R), are striated, like their body wall muscle neighbors (BWM) (Sulston J.E., Albertson, D.G. and Thomson J. N., unpublished). They contain significantly more sarcomeres than non-striated muscles and attach to the body wall cuticle at multiple sites along their length (in contrast to non-striated muscles which attach only at their ends; <a href="#MaleMusFIG16">MaleMusFIG 16</a>, <a href="#MaleMusFIG17A">17</a>, <a href="#MaleMusFIG18">18B</a>, <a href="#MaleMusFIG19">19B</a> and <a href="#MaleMusFIG20">20</a>). <br> </p> <div align="center"><a href="#MaleIntroFIG11" target="mainFrame"><img src="images/MaleMusFIG16.jpg" alt="MaleMusFIG 16 Sarcomeres of the longitudinal muscles" name="MaleMusFIG16" width="800" height="188" border="0" align="middle" class="Galborder" id="MaleMusFIG16"></a><a name="MaleMusFIG16" id="MaleMusFIG16"></a> </div> <span class="picturetitle">MaleMusFIG 16: Sarcomeres of the longitudinal muscles. </span><span class="style2"> <strong>A.</strong> Epifluorescent image from transgenic animal expressing the<em> mab-23 </em> reporter gene (transcription factor), left lateral view. (Strain source: R. Lints and S.W. Emmons.)<strong> B.</strong> Epifluorescent image from transgenic animal expressing the<em> unc-27 </em> reporter gene (Troponinl), ventral view. (Strain source: L. Jia and S.W. Emmons.)</span> <hr class="page-splits"> <div align="center"><img src="images/MaleMusFIG17A.jpg" alt="MaleMusFIG 17A Longitudinal muscles" name="MaleMusFIG17A" width="410" height="517" border="0" align="middle" class="Galborder" id="MaleMusFIG17A"><a name="MaleMusFIG17A" id="MaleMusFIG17A"></a> </div> <span class="picturetitle">MaleMusFIG 17A: Longitudinal muscles. </span><span class="style2"> Diagram , transverse view. Basal laminae not shown.</span> <div align="center"><br> <img src="images/MaleMusFIG17B.jpg" alt="MaleMusFIG17B Ultrastructure of longitudinal muscle" name="MaleMusFIG17B" width="466" height="517" border="0" align="middle" class="Galborder" id="MaleMusFIG17B"><a name="MaleMusFIG17B" id="MaleMusFIG17B"></a> </div> <span class="picturetitle">MaleMusFIG 17B: Ultrastructure of longitudinal muscle. </span><span class="style2">TEM, transverse view of boxed area in <strong>17A</strong>. Image shows attachment sites of muscle to cuticle (<em>red arrows</em>) and muscle to muscle (<em>yellow arrows</em>). (Image source: N2Y [MRC] 1024.)</span> <p>The ails and pils are joined via attachment plaques and by gap junctions to diagonal muscles (Sulston J.E., Albertson, D.G. and Thomson J. N., unpublished). The longitudinal muscles may therefore function with diagonal muscles in turning (<a href="#MaleMusFIG18">MaleMusFIG 18B</a>, <a href="#MaleMusFIG19">19B</a>). Consistent with this possibility, the posterior outer longitudinal muscles receive inputs from the rays, which have been shown to play a role in turning (<a href="#MaleMusFIG20">MaleMusFIG 20</a>; <a href="#Liu1995" target="_blank">Liu and Sternberg, 1995</a>). These NMJs occur on the muscle sarcomere, and not on muscle arms, as the neuron enters the commissures to the preanal ganglion.<br> </p> <div align="center"><img src="images/MaleMusFIG18.jpg" alt="MaleMusFIG 18 Anterior and posterior longitudinal muscles" name="MaleMusFIG18" width="800" height="518" border="0" align="middle" class="Galborder" id="MaleMusFIG18"><a name="MaleMusFIG18" id="MaleMusFIG18"></a> </div> <span class="picturetitle">MaleMusFIG 18: Anterior and posterior longitudinal muscles. </span><span class="style2"><strong>A.</strong> Low-power TEM showing the relationship of the longitudinal muscle with the diagonal and body wall muscles, transverse section. <strong>B. </strong>TEM, transverse view of boxed area in <strong>18A</strong>. (<em>Red arrow</em>) Hemidesmosome. (VNC) Ventral nerve cord; (vBWM) ventral body wall muscle. (Image source: N2Y [MRC] 595-19.)</span> <hr class="page-splits"> <div align="center"><img src="images/MaleMusFIG19.jpg" alt="MaleMusFIG 19 Caudal longitudinal muscles" name="MaleMusFIG19" width="772" height="644" border="0" align="middle" class="Galborder" id="MaleMusFIG19"><a name="MaleMusFIG19" id="MaleMusFIG19"></a> </div> <span class="picturetitle">MaleMusFIG 19: Caudal longitudinal muscles. </span><span class="style2"><strong>A. </strong>Low-power TEM showing the relationship of the caudal longitudinal muscle with the diagonal muscles, transverse section. <strong>B. </strong>TEM, higher magnification of boxed area in <strong>19A</strong>. (N) Nucleus; (PAG) pre-anal ganglion; (vBWM) ventral body wall muscle. (Image source: N2Y [MRC] 579-20.)</span> <hr class="page-splits"> <div align="center"><img src="images/MaleMusFIG20.jpg" alt="MaleMusFIG 20 NMJs of longitudinal muscles" name="MaleMusFIG20" width="497" height="596" border="0" align="middle" class="Galborder" id="MaleMusFIG20"><a name="MaleMusFIG20" id="MaleMusFIG20"></a> </div> <span class="picturetitle">MaleMusFIG 20: NMJs of longitudinal muscles. </span><span class="style2">TEM showing synapses between longitudinal muscle and R3AL commissure from the rays, transverse view.(polL) Posterior outer longitudinal; (dglL) diagonal muscle; (BWM) body wall muscle. (Image source: N2Y [MRC] L849.)</span> <hr class="page-splits"> <p><span class="subtitle"><a name="References5" id="References5"></a></span><span class="style10"><br> 5 References</span></p> <p><a name="Barr1999"></a>Barr, M.M. and Sternberg, P.W. 1999. A polycystic kidney-disease gene homologue required for male mating behaviour in <em>C. elegans</em>. Nature <strong>401: </strong>339-40. <a href="http://dx.doi.org/10.1038/43913" target="_blank">Abstract</a></p> <p><a name="Branda2000"></a>Branda, C.S. and Stern, M.J. 2000. Mechanisms controlling sex myoblast migration in <em>Caenorhabditis elegans</em> hermaphrodites. Dev. Biol. <strong>226:</strong> 137-51. <a href="http://dx.doi.org/10.1006/dbio.2000.9853" target="_blank">Article</a></p> <p><a name="Garcia2001"></a>Garcia, L.R., Mehta, P. and Sternberg, P.W. 2001. Regulation of distinct muscle behaviors controls the <em>C. elegans</em> male's copulatory spicules during mating. Cell <strong>107</strong>: 777-788. <a href="http://dx.doi.org/10.1016/S0092-8674(01)00600-6" target="_blank">Article</a></p> <p><a name="Liu1995"></a>Liu, K.S. and Sternberg, P.W. 1995. Sensory regulation of male mating behavior in <em>Caenorhabditis elegans</em>. Neuron <strong>14</strong>: 79-89 <a href="http://dx.doi.org/10.1016/0896-6273(95)90242-2" target="_blank">Article</a></p> <p><a name="Loer1993"></a>Loer, C.M. and Kenyon, C.J. 1993. Serotonin-deficient mutants and male mating behavior in the nematode <em>Caenorhabditis elegans</em>. J. Neurosci. <strong>13: </strong>5407-17. <a href="http://www.jneurosci.org/cgi/reprint/13/12/5407" target="_blank">Article</a></p> <p><a name="Reiner1995"></a>Reiner, D.J. and Thomas, J.H. 1995. Reversal of a muscle response to GABA during <em>C. elegans</em> male development. J. Neurosci. <strong>15:</strong> 6094-6102. <a href="http://www.jneurosci.org/cgi/pmidlookup?view=long&pmid=7666193" target="_blank">Article</a></p> <p><a name="Sulston1977"></a>Sulston, J.E. and Horvitz, H. R. 1977. Post-embryonic cell lineages of the nematode <em>Caenorhabditis elegans</em>. <em>Dev. Biol.</em> <strong>56</strong>: 110-156. <a href="http://www.wormatlas.org/ver1/postemblin_1977/toc.html" target="_blank">Article</a></p> <p><a name="Sulston1980"></a>Sulston, J.E., Albertson, D.G. and Thomson, J.N. 1980. The <em>Caenorhabditis elegans</em> male: Postembryonic development of nongonadal structures. Dev Biol. <strong>78</strong>: 542-576. <a href="http://www.wormatlas.org/ver1/Sulston postembmale_1980/toc.html" target="_blank">Article</a> </p> <p><a name="Sulston1983"></a>Sulston, J.E., Schierenberg, E., White J.G. and Thomson, J.N. 1983. The embryonic cell lineage of the nematode <em>Caenorhabditis elegans</em>. Dev. Biol. <strong>100</strong>: 64-119. <a href="http://www.wormatlas.org/ver1/Sulstonemblin_1983/toc.html" target="_blank">Article</a></p> <p><a name="Waterston1988"></a>Waterston, R.H. 1988. Muscle. In The nematode<em> C. elegans</em> (ed. W.B. Wood). Chapter 10. pp 281-335. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York.</p> <p><a name="White1988"></a>White, J. 1988. The Anatomy. In The nematode<em> C. elegans</em> (ed. W.B. Wood). Chapter 4. pp 81-122. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York.</p> <hr class="page-splits"></td> </tr><tr> <td align="left" class="style1"> <a href="#top"><img src="../../picts/topoff.gif" border="0" onMouseOver="this.src='../../picts/topon.gif'" onMouseOut="this.src='../../picts/topoff.gif'"> </a><br> This chapter should be cited as: Lints, R. and Hall, D.H. 2009. Male muscle system, overview. In<em> WormAtlas</em>.  doi:<a href="http://dx.doi.org/10.3908/wormatlas.2.4" target="_top">10.3908/wormatlas.2.4 </a>  <br> Edited for the web by Laura A. Herndon. Last revision: July 11, 2013. </td> </tr></table> </td> </tr></table>   </td></tr><tr><td>  <table cellpadding="0" cellspacing="0" border="0" width="100%"><tr class="printhide"><td class="pagebar-bottom"> <img src="../../picts/spacer.gif" width="10" height="1" alt="image"><br> </td></tr></table>  </td></tr><tr><td class="shadow-horizontal">  <table cellpadding="6" cellspacing="0" border="0" width="100%"><tr><td align="left" valign="top"> <script language="JavaScript" type="text/javascript" src="../../copyright.js"></script> </td><td align="right" valign="top"> </td></tr></table>  </td></tr></table>  <script src="/google_analytics.js"></script> </BODY></HTML>