scholarly journals Evolutionary dynamics of male reproductive genes in the Drosophila virilis subgroup

2017 ◽  
Author(s):  
Yasir H. Ahmed-Braimah ◽  
Robert L. Unckless ◽  
Andrew G. Clark

AbstractPostcopulatory sexual selection (PCSS) is a potent evolutionary force that can drive rapid changes of reproductive genes within species, and thus has the potential to generate reproductive incompatibilities between species. Male seminal fluid proteins (SFPs) are major players in postmating interactions, and likely the main targets of PCSS in males. The virilis subgroup of Drosophila exhibits strong interspecific gametic incompatibilities, and can serve as a model to study the genetic basis of PCSS and gametic isolation. However, reproductive genes in this group have not been characterized. Here we use short-read RNA sequencing of male reproductive organs to examine the evolutionary dynamics of reproductive genes in members of the virilis subgroup: D. americana, D. lummei, D. novamexicana, and D. virilis. For each of the three male reproductive organs (accessory glands, ejaculatory bulb, and testes), we identify genes that show strong expression bias in a given tissue relative to the remaining tissues. We find that the majority of male reproductive transcripts are testes-biased, accounting for ~15% of all annotated genes. Ejaculatory bulb-biased transcripts largely code for lipid metabolic enzymes, and contain orthologs of the D. melanogaster ejaculatory bulb protein, Peb-me, which is involved in mating-plug formation. In addition, we identify 71 candidate SFPs, and show that this set of genes has the highest rate of nonsynonymous codon substitution relative to testes- and ejaculatory bulb-biased genes. Furthermore, these SFPs are underrepresented on the X chromosome and are enriched for proteolytic enzymes, which is consistent with SFPs in other insect species. Surprisingly, we find 35 D. melanogaster SFPs with conserved accessory gland expression in the virilis group, suggesting these genes may have conserved reproductive roles in Drosophila. Finally, we show that several of the SFPs that have the highest rate of nonsynonymous codon substitutions reside on the centromeric half of chromosome 2, which contributes to paternal gametic incompatibility between species. Our results suggest that SFPs are under strong selection in the virilis group, and likely play a major role in PCSS and/or gametic isolation.

Author(s):  
Yasir H Ahmed-Braimah ◽  
Mariana F Wolfner ◽  
Andrew G Clark

Abstract In many animal species, females undergo physiological and behavioral changes after mating. Some of these changes are driven by male-derived seminal fluid proteins and are critical for fertilization success. Unfortunately, our understanding of the molecular interplay between female and male reproductive proteins remains inadequate. Here, we analyze the postmating response in a Drosophila species that has evolved strong gametic incompatibility with its sister species; Drosophila novamexicana females produce only ∼1% fertilized eggs in crosses with Drosophila americana males, compared to ∼98% produced in within-species crosses. This incompatibility is likely caused by mismatched male and female reproductive molecules. In this study, we use short-read RNA sequencing to examine the evolutionary dynamics of female reproductive genes and the postmating transcriptome response in crosses within and between species. First, we found that most female reproductive tract genes are slow-evolving compared to the genome average. Second, postmating responses in con- and heterospecific matings are largely congruent, but heterospecific matings induce expression of additional stress-response genes. Some of those are immunity genes that are activated by the Imd pathway. We also identify several genes in the JAK/STAT signaling pathway that are induced in heterospecific, but not conspecific mating. While this immune response was most pronounced in the female reproductive tract, we also detect it in the female head and ovaries. These results show that the female’s postmating transcriptome-level response is determined in part by the genotype of the male, and that divergence in male reproductive genes and/or traits can have immunogenic effects on females.


Author(s):  
Yasir H. Ahmed-Braimah ◽  
Mariana F. Wolfner ◽  
Andrew G. Clark

AbstractIn many animal species, females undergo physiological and behavioral changes after mating. Some of these changes are driven by male-derived seminal fluid proteins, and are critical for fertilization success. Unfortunately, our understanding of the molecular interplay between female and male reproductive proteins remains superficial. Here we analyze the post-mating response in a Drosophila species that has evolved strong gametic incompatibility with its sister species; D. novamexicana females produce only 1% fertilized eggs in crosses with D. americana males, compared to ~98% produced in within-species crosses. This incompatibility is likely caused by mismatched male and female reproductive molecules. In this study we use short-read RNA sequencing to examine the evolutionary dynamics of female reproductive genes and the post-mating transcriptome response in crosses within and between species. First, we found that most female reproductive tract genes are slow-evolving compared to the genome average. Second, post-mating responses in con- and heterospecific matings are largely congruent, but heterospecific mating induces expression of additional stress-response genes. Some of those are immunity genes that are activated by the Imd pathway. We also identify several genes in the JAK/STAT signaling pathway that are induced in heterospecific, but not conspecific mating. While this immune response was most pronounced in the female reproductive tract, we also detect it in the female head and ovaries. Our results show that the female’s post-mating transcriptome-level response is determined in part by the genotype of the male, and that divergence in male reproductive genes and/or traits can have immunogenic effects on females.


Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 175
Author(s):  
Alexander P. Rezvykh ◽  
Sergei Yu. Funikov ◽  
Lyudmila A. Protsenko ◽  
Dina A. Kulikova ◽  
Elena S. Zelentsova ◽  
...  

Pericentromeric heterochromatin in Drosophila generally consists of repetitive DNA, forming the environment associated with gene silencing. Despite the expanding knowledge of the impact of transposable elements (TEs) on the host genome, little is known about the evolution of pericentromeric heterochromatin, its structural composition, and age. During the evolution of the Drosophilidae, hundreds of genes have become embedded within pericentromeric regions yet retained activity. We investigated a pericentromeric heterochromatin fragment found in D. virilis and related species, describing the evolution of genes in this region and the age of TE invasion. Regardless of the heterochromatic environment, the amino acid composition of the genes is under purifying selection. However, the selective pressure affects parts of genes in varying degrees, resulting in expansion of gene introns due to TEs invasion. According to the divergence of TEs, the pericentromeric heterochromatin of the species of virilis group began to form more than 20 million years ago by invasions of retroelements, miniature inverted repeat transposable elements (MITEs), and Helitrons. Importantly, invasions into the heterochromatin continue to occur by TEs that fall under the scope of piRNA silencing. Thus, the pericentromeric heterochromatin, in spite of its ability to induce silencing, has the means for being dynamic, incorporating the regions of active transcription.


2010 ◽  
Vol 151 (39) ◽  
pp. 1573-1579
Author(s):  
Ákos Jakobovits ◽  
Antal Jakobovits

A szerzők a központi idegrendszer, a tesztoszteron és származékainak szerepét tárgyalják a férfi nemi szervek méhen belüli fejlődésében. A férfi személyiségét meghatározó jellegzetességek először az emberi fejlődés magzati stádiumában jelentkeznek. Ezek kialakulása a gyermekkorban folytatódik. Pubertás után ezek növekvő mértékben válnak nyilvánvalóvá, és az egyén élete folyamán túlsúlyban maradnak. Az említett folyamatok mind a férfias fenotípust, mind a férfias magatartást befolyásolják. A tesztoszteron és származékai kontrollálják a férfi nemi szervek fejlődését. Hiányuk a női nemi jellegzetességek túlsúlyához vezet, a férfi nemi kromoszómakép ellenére. E jelenségek típusos példája a testicularis feminisatio klinikai képe. Jelen tanulmány különleges figyelmet szentel a reprodukciós szervek azon rendellenességeinek, amelyek a magzatokban ultrahanggal azonosíthatók. Ezen anomáliák legtöbbje antenatalisan hatásosan nem kezelhető. Azok a rendellenességek, amelyek a méhen kívüli életben sem gyógyíthatók, a terhességmegszakítás javallatát képezhetik, amennyiben ultrahangvizsgálattal a kora terhességben kimutathatók. Orv. Hetil., 2010, 39, 1573–1579.


2021 ◽  
Vol 140 (1) ◽  
Author(s):  
Christian Klug ◽  
Günter Schweigert ◽  
Helmut Tischlinger ◽  
Helmut Pochmann

AbstractAmmonoid soft parts have been rarely described. Here, we document the soft parts of a perisphinctid ammonite from the early Tithonian of Wintershof near Eichstätt (Germany). This exceptional preservation was enabled by the special depositional conditions in the marine basins of the Solnhofen Archipelago. Here, we document this find and attempt to homologize its parts with various organs such as the digestive tract, reproductive organs, the mantle cavity with gills, and the hyponome, with differing degrees of reservation. Alternative interpretations are also taken into account. We suggest that the soft parts were separated from the conch either taphonomically (following necrolytical processes affecting the attachment structures) or during a failed predation, where a predator (fish or coleoid) removed the soft parts from the conch but then dropped them. This find is interesting because it adds to the knowledge of ammonite anatomy, which is normally hidden in the conch. The reproductive organs show traces of what might have been spermatophores, thus supporting the hypothesis that the microconchs represented the males.


2010 ◽  
Vol 33 (2) ◽  
pp. 279-287 ◽  
Author(s):  
D. J. MacLeod ◽  
R. M. Sharpe ◽  
M. Welsh ◽  
M. Fisken ◽  
H. M. Scott ◽  
...  

1998 ◽  
Vol 36 (1) ◽  
pp. 44-49 ◽  
Author(s):  
P. Piyachaturawat ◽  
A. Timinkul ◽  
A. Chuncharunee ◽  
A. Suksamrarn

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