scholarly journals Integrated and independent evolution of heteromorphic sperm types

2013 ◽  
Vol 280 (1769) ◽  
pp. 20131647 ◽  
Author(s):  
Allen J. Moore ◽  
Leonardo D. Bacigalupe ◽  
Rhonda R. Snook

Sperm are a simple cell type with few components, yet they exhibit tremendous between-species morphological variation in those components thought to reflect selection in different fertilization environments. However, within a species, sperm components are expected to be selected to be functionally integrated for optimal fertilization of eggs. Here, we take advantage of within-species variation in sperm form and function to test whether sperm components are functionally and genetically integrated both within and between sperm morphologies using a quantitative genetics approach. Drosophila pseudoobscura males produce two sperm types with different functions but which positively interact together in the same fertilization environment; the long eusperm fertilizes eggs and the short parasperm appear to protect eusperm from a hostile female reproductive tract. Our analysis found that all sperm traits were heritable, but short sperm components exhibited evolvabilities 10 times that of long sperm components. Genetic correlations indicated functional integration within, but not between, sperm morphs. These results suggest that sperm, despite sharing a common developmental process, can become developmentally and functionally non-integrated, evolving into separate modules with the potential for rapid and independent responses to selection.

2018 ◽  
Vol 19 (12) ◽  
pp. 4097 ◽  
Author(s):  
Karl Kerns ◽  
Michal Zigo ◽  
Peter Sutovsky

The importance of zinc for male fertility only emerged recently, being propelled in part by consumer interest in nutritional supplements containing ionic trace minerals. Here, we review the properties, biological roles and cellular mechanisms that are relevant to zinc function in the male reproductive system, survey available peer-reviewed data on nutritional zinc supplementation for fertility improvement in livestock animals and infertility therapy in men, and discuss the recently discovered signaling pathways involving zinc in sperm maturation and fertilization. Emphasis is on the zinc-interacting sperm proteome and its involvement in the regulation of sperm structure and function, from spermatogenesis and epididymal sperm maturation to sperm interactions with the female reproductive tract, capacitation, fertilization, and embryo development. Merits of dietary zinc supplementation and zinc inclusion into semen processing media are considered with livestock artificial insemination (AI) and human assisted reproductive therapy (ART) in mind. Collectively, the currently available data underline the importance of zinc ions for male fertility, which could be harnessed to improve human reproductive health and reproductive efficiency in agriculturally important livestock species. Further research will advance the field of sperm and fertilization biology, provide new research tools, and ultimately optimize semen processing procedures for human infertility therapy and livestock AI.


2004 ◽  
Vol 16 (4) ◽  
pp. 447 ◽  
Author(s):  
Lindsay Gillan ◽  
W. M. Chis Maxwell ◽  
Gareth Evans

Many years of research have been devoted to improving the fertility of preserved semen of small ruminants. There have been few significant advances in preservation in recent times, but considerable knowledge has been gained on the effect of preservation on the structure and function of spermatozoa. It has become evident that preservation greatly affects many sperm attributes, such as motility, respiratory activity, membrane status and DNA quality. Consequently, viability is reduced, transport in the female reproductive tract is inhibited, the timing of fertilisation is altered and embryo development is affected following insemination of preserved, compared to fresh spermatozoa. A greater understanding of their functional condition may lead to the development of methods of preventing these alterations or to improved methods of using the preserved spermatozoa for artificial insemination in their altered state.


Reproduction ◽  
2012 ◽  
Vol 143 (5) ◽  
pp. 559-576 ◽  
Author(s):  
Warren B Nothnick

Proper development and function of the female reproductive tract are essential for successful reproduction. Regulation of the differentiated functions of the organs that make up the female reproductive tract is well established to occur at multiple levels including transcription, translation, and posttranslational modifications. Micro-RNA (miRNA)-mediated posttranscriptional gene regulation has emerged as a fundamental mechanism controlling normal tissue development and function. Emerging evidence indicates that miRNAs are expressed within the organs of the female reproductive tract where they function to regulate cellular pathways necessary for proper function of these organs. In this review, the functional significance of miRNAs in the development and function of the organs of the female reproductive tract is discussed. Initial discussion focuses on the role of miRNAs in the development of the organs of the female reproductive tract highlighting recent studies that clearly demonstrate that mice with disrupted Dicer1 expression are sterile, fail to develop uterine glands, and have muted estrogen responsiveness. Next, emphasis moves to discussion on our current knowledge on the characterization of miRNA expression in each of the organs of the female reproductive tract. When possible, information is presented and discussed with respect to regulation, function, and/or functional targets of these miRNA within each specific organ of the female reproductive tract.


Reproduction ◽  
2011 ◽  
Vol 141 (6) ◽  
pp. 725-735 ◽  
Author(s):  
Lorraine Frew ◽  
Sarah J Stock

Antimicrobial peptides (AMPs) are small proteins produced by epithelial surfaces and inflammatory cells, which have broad-spectrum antimicrobial and immunomodulatory activities. They are known to be important in a number of infectious and inflammatory conditions and have been shown to be present in a number of sites throughout the female reproductive tract. Inflammation and infection are associated with a number of complications of pregnancy including preterm labor, and AMPs may play a key role in maintaining and protecting pregnancy. The aim of this review is to describe the expression and function of AMPs in the pregnant female reproductive tract and their relation to preterm labor.


2020 ◽  
Vol 375 (1813) ◽  
pp. 20200079
Author(s):  
Christopher R. Friesen ◽  
Ariel F. Kahrl ◽  
Mats Olsson

Multiple paternity is ubiquitous within the polyphyletic group called ‘reptiles', especially within the lizards and snakes. Therefore, the probability of sperm competition occurring, and being intense, is high. Squamates exhibit a diversity of tactics to ensure fertilization success in the face of sperm competition. The duration of female sperm storage, which can be many months and even years in some species, remains an enigma. Here, we emphasize some mechanisms that might affect patterns of paternity, the source and function of ejaculates and features of the female reproductive tract that may aid in long-term sperm storage. In doing so, we present a new analysis of the relationship between sperm size, the strength of sperm competition and the duration of female sperm storage. Lizards and snakes are a diverse group that has provided many excellent models for the study of an array of life-history strategies. However, when it comes to postcopulatory sexual selection, there is much left to discover. This article is part of the theme issue ‘Fifty years of sperm competition'.


2012 ◽  
Vol 32 (39) ◽  
pp. 13608-13620 ◽  
Author(s):  
M. E. Estevez ◽  
P. M. Fogerson ◽  
M. C. Ilardi ◽  
B. G. Borghuis ◽  
E. Chan ◽  
...  

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