scholarly journals Izumo1 and Juno: the evolutionary origins and coevolution of essential sperm–egg binding partners

2015 ◽  
Vol 2 (12) ◽  
pp. 150296 ◽  
Author(s):  
Phil Grayson
Keyword(s):  
Knockout Mice ◽  
Folate Receptor ◽  
Rapid Evolution ◽  
Positive Darwinian Selection ◽  
Reproductive Proteins ◽  
Evolutionary Forces ◽  
Evolutionary Origins ◽  
Mammalian Sperm ◽  
Binding Partners ◽  
Genomic Analyses

Reproductive proteins are among the most rapidly evolving classes of proteins. For a subset of these, rapid evolution is driven by positive Darwinian selection despite vital, well-conserved, reproductive functions. Izumo1 is the only essential sperm–egg fusion protein currently known on mammalian sperm, and its egg receptor (Juno; formerly Folr4) was recently discovered. Male knockout mice for Izumo1 and female knockout mice for Juno are both healthy but sterile. Here, both sperm–egg binding proteins are shown to be evolving under positive selection. Within mammals, coevolution of Izumo1 and Juno is also uncovered, suggesting that similar forces have shaped the evolutionary histories of these binding partners within Mammalia. Additionally, genomic analyses reveal an ancient origin for the Izumo gene family, initially reported as conserved exclusively in mammals. Newly identified Izumo1 orthologues could serve reproductive functions in birds, fish and reptiles. Surprisingly, these same analyses support Juno's presence in mammals alone, suggesting a recent mammalian-specific duplication and neofunctionalization of the ancestral folate receptor. Despite the indispensability of their reproductive interaction, and their apparent coevolution within Mammalia, this binding pair arose through strikingly different evolutionary forces.

scholarly journals Rapid evolution and molecular convergence in cryptorchidism-related genes associated with inherently undescended testes in mammals

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Simin Chai ◽  
Ran Tian ◽  
Juanjuan Bi ◽  
Shixia Xu ◽  
Guang Yang ◽  
...  
Keyword(s):  
Muscle Development ◽  
Rapid Evolution ◽  
Genetic Material ◽  
Comparative Genomic ◽  
Testicular Descent ◽  
Ancestral State ◽  
Undescended Testes ◽  
Genomic Analyses ◽  
Genetic Mechanisms ◽  
Molecular Convergence

Abstract Background The mammalian testis is an important male exocrine gland and spermatozoa-producing organ that usually lies in extra-abdominal scrotums to provide a cooler environment for spermatogenesis and sperm storage. Testicles sometimes fail to descend, leading to cryptorchidism. However, certain groups of mammals possess inherently ascrotal testes (i.e. testes that do not descend completely or at all) that have the same physiological functions as completely descended scrotal testes. Although several anatomical and hormonal factors involved in testicular descent have been studied, there is still a paucity of comprehensive research on the genetic mechanisms underlying the evolution of testicular descent in mammals and how mammals with ascrotal testes maintain their reproductive health. Results We performed integrative phenotypic and comparative genomic analyses of 380 cryptorchidism-related genes and found that the mammalian ascrotal testes trait is derived from an ancestral scrotal state. Rapidly evolving genes in ascrotal mammals were enriched in the Hedgehog pathway—which regulates Leydig cell differentiation and testosterone secretion—and muscle development. Moreover, some cryptorchidism-related genes in ascrotal mammals had undergone positive selection and contained specific mutations and indels. Genes harboring convergent/parallel amino acid substitutions between ascrotal mammals were enriched in GTPase functions. Conclusions Our results suggest that the scrotal testis is an ancestral state in mammals, and the ascrotal phenotype was derived multiple times in independent lineages. In addition, the adaptive evolution of genes involved in testicular descent and the development of the gubernaculum contributed to the evolution of ascrotal testes. Accurate DNA replication, the proper segregation of genetic material, and appropriate autophagy are the potential mechanisms for maintaining physiological normality during spermatogenesis in ascrotal mammals. Furthermore, the molecular convergence of GTPases is probably a mechanism in the ascrotal testes of different mammals. This study provides novel insights into the evolution of the testis and scrotum in mammals and contributes to a better understanding of the pathogenesis of cryptorchidism in humans.

scholarly journals The sperm protein SPACA4 is required for efficient fertilization in mice

2021 ◽  
Author(s):  
Sarah Herberg ◽  
Yoshitaka Fujihara ◽  
Andreas Blaha ◽  
Karin Panser ◽  
Kiyonari Kobayashi ◽  
...  
Keyword(s):  
Zona Pellucida ◽  
Knockout Mice ◽  
Mammalian Species ◽  
Wild Type ◽  
Sperm Protein ◽  
Mammalian Sperm ◽  
Fundamental Process ◽  
Mammalian Fertilization

Fertilization is the fundamental process that initiates the development of a new individual in all sexually reproducing species. Despite its importance, our understanding of the molecular players that govern mammalian sperm-egg interaction is incomplete, partly because many of the essential factors found in non-mammalian species do not have obvious mammalian homologs. We have recently identified the Ly6/uPAR protein Bouncer as a new, essential fertilization factor in zebrafish (Herberg et al., 2018). Here, we show that Bouncer's homolog in mammals, SPACA4, is also required for efficient fertilization in mice. In contrast to fish, where Bouncer is expressed specifically in the egg, SPACA4 is expressed exclusively in the testis. Male knockout mice are severely sub-fertile, and sperm lacking SPACA4 fail to fertilize wild-type eggs in vitro. Interestingly, removal of the zona pellucida rescues the fertilization defect of Spaca4-deficient sperm in vitro, indicating that SPACA4 is not required for the interaction of sperm and the oolemma but rather of sperm and zona pellucida. Our work identifies SPACA4 as an important sperm protein necessary for zona pellucida penetration during mammalian fertilization.

scholarly journals An integrative genomic analysis of the Longshanks selection experiment for longer limbs in mice

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
João PL Castro ◽  
Michelle N Yancoskie ◽  
Marta Marchini ◽  
Stefanie Belohlavy ◽  
Layla Hiramatsu ◽  
...  
Keyword(s):  
Bone Growth ◽  
Rapid Evolution ◽  
Genomic Analysis ◽  
Selection Response ◽  
Major Effect ◽  
Selection Experiment ◽  
Genomic Analyses ◽  
Selection Experiments ◽  
Polygenic Adaptation ◽  
History Of

Evolutionary studies are often limited by missing data that are critical to understanding the history of selection. Selection experiments, which reproduce rapid evolution under controlled conditions, are excellent tools to study how genomes evolve under selection. Here we present a genomic dissection of the Longshanks selection experiment, in which mice were selectively bred over 20 generations for longer tibiae relative to body mass, resulting in 13% longer tibiae in two replicates. We synthesized evolutionary theory, genome sequences and molecular genetics to understand the selection response and found that it involved both polygenic adaptation and discrete loci of major effect, with the strongest loci tending to be selected in parallel between replicates. We show that selection may favor de-repression of bone growth through inactivating two limb enhancers of an inhibitor, Nkx3-2. Our integrative genomic analyses thus show that it is possible to connect individual base-pair changes to the overall selection response.

scholarly journals The Macrogenoeconomics of Comparative Development

2018 ◽  
Vol 56 (3) ◽  
pp. 1119-1155 ◽  
Author(s):  
Quamrul H. Ashraf ◽  
Oded Galor
Keyword(s):  
Economic Development ◽  
Economic Performance ◽  
Human Population ◽  
Population Diversity ◽  
Comparative Development ◽  
Neolithic Revolution ◽  
Evolutionary Forces ◽  
Evolutionary Origins ◽  
Anatomically Modern Humans ◽  
Out Of Africa

The importance of evolutionary forces for comparative economic performance across societies has been the focus of a vibrant literature, highlighting the roles played by the Neolithic Revolution as well as the prehistoric “out of Africa” migration of anatomically modern humans in generating worldwide variations in the composition of human traits. This essay provides an overview of the literature on the macrogenoeconomics of comparative development, underscoring the significance of evolutionary processes and human population diversity in generating differential paths of economic development across societies. Furthermore, it examines the contribution of Nicholas Wade’s recent hypothesis, regarding the evolutionary origins of comparative development, to this important line of research. ( JEL N10, N30, O11, Z10)

scholarly journals Multiple evolutionary origins of giant viruses

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1840 ◽  
Author(s):  
Eugene V. Koonin ◽  
Natalya Yutin
Keyword(s):  
Life Forms ◽  
Translation System ◽  
Dna Viruses ◽  
Evolutionary Forces ◽  
Evolutionary Origins ◽  
Cellular Life ◽  
Giant Viruses ◽  
Nucleocytoplasmic Large Dna Viruses ◽  
Phylogenomic Analyses ◽  
Definition Of

The nucleocytoplasmic large DNA viruses (NCLDVs) are a monophyletic group of diverse eukaryotic viruses that reproduce primarily in the cytoplasm of the infected cells and include the largest viruses currently known: the giant mimiviruses, pandoraviruses, and pithoviruses. With virions measuring up to 1.5 μm and genomes of up to 2.5 Mb, the giant viruses break the now-outdated definition of a virus and extend deep into the genome size range typical of bacteria and archaea. Additionally, giant viruses encode multiple proteins that are universal among cellular life forms, particularly components of the translation system, the signature cellular molecular machinery. These findings triggered hypotheses on the origin of giant viruses from cells, likely of an extinct fourth domain of cellular life, via reductive evolution. However, phylogenomic analyses reveal a different picture, namely multiple origins of giant viruses from smaller NCLDVs via acquisition of multiple genes from the eukaryotic hosts and bacteria, along with gene duplication. Thus, with regard to their origin, the giant viruses do not appear to qualitatively differ from the rest of the virosphere. However, the evolutionary forces that led to the emergence of virus gigantism remain enigmatic.

scholarly journals Why Do Some Vertebrates Have Microchromosomes?

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2182
Author(s):  
Kornsorn Srikulnath ◽  
Syed Farhan Ahmad ◽  
Worapong Singchat ◽  
Thitipong Panthum
Keyword(s):  
Karyotype Evolution ◽  
Current Knowledge ◽  
Genome Structure ◽  
Origin And Evolution ◽  
Evolutionary Forces ◽  
Evolutionary Origins ◽  
Open Questions ◽  
Huge Impact ◽  
High Gene ◽  
Living Species

With more than 70,000 living species, vertebrates have a huge impact on the field of biology and research, including karyotype evolution. One prominent aspect of many vertebrate karyotypes is the enigmatic occurrence of tiny and often cytogenetically indistinguishable microchromosomes, which possess distinctive features compared to macrochromosomes. Why certain vertebrate species carry these microchromosomes in some lineages while others do not, and how they evolve remain open questions. New studies have shown that microchromosomes exhibit certain unique characteristics of genome structure and organization, such as high gene densities, low heterochromatin levels, and high rates of recombination. Our review focuses on recent concepts to expand current knowledge on the dynamic nature of karyotype evolution in vertebrates, raising important questions regarding the evolutionary origins and ramifications of microchromosomes. We introduce the basic karyotypic features to clarify the size, shape, and morphology of macro- and microchromosomes and report their distribution across different lineages. Finally, we characterize the mechanisms of different evolutionary forces underlying the origin and evolution of microchromosomes.

scholarly journals Rapid divergence of the copulation proteins in the Drosophila dunni group is associated with hybrid post-mating-prezygotic incompatibilities

2020 ◽  
Author(s):  
Tom Hill ◽  
Hazel-Lynn Rosales-Stephens ◽  
Robert L. Unckless
Keyword(s):  
Seminal Fluid ◽  
Rapid Evolution ◽  
Species Group ◽  
Egg Laying ◽  
Reproductive Proteins ◽  
Seminal Fluid Proteins ◽  
Prezygotic Isolation ◽  
Caribbean Islands ◽  
Female Survival ◽  
Rapid Divergence

AbstractProteins involved in post-copulatory interactions between males and females are among the fastest evolving genes in many species and this has been attributed to reproductive conflict. Likely as a result, these proteins are frequently involved in cases of post-mating-prezygotic isolation between species. The Drosophila dunni subgroup consists of a dozen recently diverged species found across the Caribbean islands with varying levels of hybrid incompatibility. We sought to examine how post-mating-prezygotic factors are involved in isolation among members of this species group. We performed experimental crosses between species in the dunni group and find evidence of hybrid inviability. We also find an insemination reaction-like response preventing egg laying and leading to reduced female survival post-mating. To identify that genes may be involved in these incompatibilities, we sequenced and assembled the genomes of four species in the dunni subgroup and looked for signals of rapid evolution between species. Despite low levels of divergence, we found evidence of rapid evolution and divergence of some reproductive proteins, specifically the seminal fluid proteins. This suggests post-mating-prezygotic isolation as a barrier for gene flow between even the most closely related species in this group and seminal fluid proteins as a possible culprit.

scholarly journals Selection constrains high rates of satellite DNA mutation in Daphnia pulex

2017 ◽  
Author(s):  
Jullien M. Flynn ◽  
Ian Caldas ◽  
Melania E. Cristescu ◽  
Andrew G. Clark
Keyword(s):  
Satellite Dna ◽  
Related Species ◽  
Rapid Evolution ◽  
Daphnia Pulex ◽  
Selective Constraint ◽  
Mutation Rates ◽  
Stabilizing Selection ◽  
Closely Related Species ◽  
Dna Mutation ◽  
Evolutionary Forces

AbstractA long-standing evolutionary puzzle is that all eukaryotic genomes contain large amounts of tandemly-repeated satellite DNA whose composition varies greatly among even closely related species. To elucidate the evolutionary forces governing satellite dynamics, quantification of the rates and patterns of mutations in satellite DNA copy number and tests of its selective neutrality are necessary. Here we used whole-genome sequences of 28 mutation accumulation (MA) lines of Daphnia pulex in addition to six isolates from a non-MA population originating from the same progenitor to both estimate mutation rates of abundances of satellite sequences and evaluate the selective regime acting upon them. We found that mutation rates of individual satellite sequence “kmers” were both high and highly variable, ranging from additions/deletions of 0.29 – 105 copies per generation (reflecting changes of 0.12 - 0.80 percent per generation). Our results also provide evidence that new kmer sequences are often formed from existing ones. The non-MA population isolates showed a signal of either purifying or stabilizing selection, with 33 % lower variation in kmer abundance on average than the MA lines, although the level of selective constraint was not evenly distributed across all kmers. The changes between many pairs of kmers were correlated, and the pattern of correlations was significantly different between the MA lines and the non-MA population. Our study demonstrates that kmer sequences can experience extremely rapid evolution in abundance, which can lead to high levels of divergence in genome-wide satellite DNA composition between closely related species.

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