Mytilus protamine-like sperm-specific protein genes are multicopy, dispersed, and closely associated with hypervariable RFLP regions.
Protamine-like sperm packaging proteins replace somatic histones during spermatogenesis, and although the proteins have been well-characterized in many marine invertebrate species, little is known of the arrangement of the genes. The research described here was designed to determine the sequence and structure of the protamine-like PL-III (or "phi 1") gene in marine mussels (Mytilus spp). The PL-III sequence was found to be extremely variable not only among the closely related Mytilus species, but also within species and populations. The variation observed among eight PL-III sequences from a single individual indicated that PL-III was probably multiple-copied. Southern analysis confirmed that PL-III, and another protamine-like gene, (PL-II), were multicopy and dispersed, as well as associated with a hypervariable element. Some PL-III genes are also arranged in nontandem clusters, and the spacer regions are probably the source of the hypervariable nature of the Southern blots. The arrangement of the protamine-like genes in Mytilus appears to be closer to that reported for histones than protamines; however, their association with a hypervariable element is novel.
Heath
D D
DD
Biology Program, College of Science and Management, University of Northern British Columbia, Canada. heath@unbc.ca
Hilbish
T J
TJ
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D049872:Bivalvia / Q000235:genetics* / Q000502:physiology; D017124:Conserved Sequence; D004268:DNA-Binding Proteins; D014644:Genetic Variation; D006657:Histones / Q000235:genetics; D008297:Male; D008969:Molecular Sequence Data; D005810:Multigene Family; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D011479:Protamines / Q000737:chemistry / Q000235:genetics*; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D013091:Spermatogenesis
D004268:DNA-Binding Proteins; D006657:Histones; D009687:Nuclear Proteins; D011479:Protamines; C093295:protamine-like protein III; C068699:PL-II protein, Mytilus