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You searched for subject:(accessory sperm). Showing records 1 – 3 of 3 total matches.

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McMaster University

1. Miller, Jessica. Accessory glands and sperm competition.

Degree: MSc, 2017, McMaster University

Sperm competition is a widely-recognized and powerful selective force. Male accessory glands are organs found across animal taxa that can influence sperm performance, and thus may be selected for in competitive contexts. In fishes, these organs are in fact rare, but display great diversity in form and function across species. Although the accessory gland is known to play a role in mate attraction, parental care, fertilization, or post-copulatory competition in a few select species, the role of this organ remains a mystery in most species. Many fishes with accessory glands also exhibit alternative reproductive tactics (ARTs), which add an extra layer of complexity to how species respond to sperm competition. Because males of different ARTs typically experience different levels of sperm competition risk, it’s possible they may differentially invest in accessory glands to overcome this competition. In this thesis, I used the plainfin midshipman fish (Porichthys notatus), a species with both ARTs and an accessory gland, to experimentally investigate the role of the accessory gland in sperm competition and uncover how this organ may differ between ARTs. Over a two-year period, I studied tactic-specific investment in the accessory gland in fish from the beaches of British Columbia. I also examined the effects of seminal fluid, produced in part by the accessory gland, on sperm performance and morphology. I found that males adopting the ‘guarder’ male tactic invested more in one region (the lobules) of this organ, while males adopting the smaller ‘sneaker’ male tactic invested more the other region of the gland (the nodes). Using data collected over five years, I found that guarder males also invested more in their whole accessory glands. Additionally, I report that sperm swam faster in the presence of seminal fluid, and seminal fluid increased sperm head size in both male tactics and increased midpiece size in guarder males. These results suggest that the plainfin midshipman accessory gland may have dual functions, one of which may be to aid sperm competitive ability through enhancements in swimming speed and potentially more successful sperm morphology. Taken together, the results of my thesis improve our knowledge of the role of non-sperm components like seminal fluid and the accessory gland in sperm competition, and demonstrate how species with ARTs can have varying physiological responses to such competition. Only a handful of studies have considered the effects of seminal fluid on sperm performance. By examining sperm competition in a more biologically relevant way and incorporating the effects of a little-studied organ that impacts sperm competition, we should be able to more generally and accurately appreciate the dynamics of post-copulatory competition and fertilization.

Thesis

Master of Science (MSc)

Advisors/Committee Members: Balshine, Sigal, Psychology.

Subjects/Keywords: sperm; sperm competition; fish biology; fish physiology; alternative reproductive tactics; seminal fluid; accessory gland; plainfin midshipman; toadfish; seminal vesicle; sperm energetics; sperm morphology

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APA (6th Edition):

Miller, J. (2017). Accessory glands and sperm competition. (Masters Thesis). McMaster University. Retrieved from http://hdl.handle.net/11375/23453

Chicago Manual of Style (16th Edition):

Miller, Jessica. “Accessory glands and sperm competition.” 2017. Masters Thesis, McMaster University. Accessed April 11, 2021. http://hdl.handle.net/11375/23453.

MLA Handbook (7th Edition):

Miller, Jessica. “Accessory glands and sperm competition.” 2017. Web. 11 Apr 2021.

Vancouver:

Miller J. Accessory glands and sperm competition. [Internet] [Masters thesis]. McMaster University; 2017. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/11375/23453.

Council of Science Editors:

Miller J. Accessory glands and sperm competition. [Masters Thesis]. McMaster University; 2017. Available from: http://hdl.handle.net/11375/23453


University of Georgia

2. Mack, Paul Douglas. Sperm competition and the role of females in Drosophila melanogaster.

Degree: 2014, University of Georgia

Although the phenomenon of sperm competition, the post-mating interaction of ejaculates within multiply mated females, has been studied extensively over the past 30 years, we still have much to learn about the mechanisms underlying sperm competition. Until very recently the majority of research has focused on male aspects of sperm competition. Here we add to the growing body of evidence for a significant female role in the outcome of sperm competition, specifically, and reproductive decisions, in general. First, we show that the ability of male Drosophila melanogaster to incapacitate stored sperm when they mate with previously mated females varies with male genotype and with the time interval since the female last mated. Second, we demonstrate the importance of the age of female D. melanogaster in the outcome of sperm competition. We explicitly tested the effect of age on the proportion of paternity achieved by the last male to mate with the female. However, our result indirectly supports the conclusion that female age may have more significant impacts on the reproductive success of previous (vs. last) males to mate with a female. Third, we test the hypothesis that first (e.g., prior) male paternity, or sperm defense, should be negatively correlated with the degree of relatedness between members of a mated pair in D. melanogaster. We provide the strongest evidence to date for the significance role of genetic relatedness on sperm competitive ability. In addition, taken together, our results from both the sperm incapacitation study and the relatedness study strongly suggest female genotype x male genotype interactions, although they do not explicitly test the hypothesis that such interactions exist. In addition to our investigations of sperm competition, we include a study of the age-specificity of novel mutations on male mating ability and fecundity. In that study, we detail the age-specific effect of cumulative novel mutations acting on both traits. Our result suggests that although age-specificity is present, the affect appears to be transient. Overall, we demonstrate the importance of female age and genotype as well as male genotype, on the outcome of several important reproductive interactions.

Subjects/Keywords: intersexual conflict; Drosophila melanogaster; sperm competition; accessory gland proteins; genetic relatedness; sperm selection; Aging; fecundity; male mating ability; mutation accumulation; senescence. female genotype; sperm offense; sperm defense; spe

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Mack, P. D. (2014). Sperm competition and the role of females in Drosophila melanogaster. (Thesis). University of Georgia. Retrieved from http://hdl.handle.net/10724/20381

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Mack, Paul Douglas. “Sperm competition and the role of females in Drosophila melanogaster.” 2014. Thesis, University of Georgia. Accessed April 11, 2021. http://hdl.handle.net/10724/20381.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Mack, Paul Douglas. “Sperm competition and the role of females in Drosophila melanogaster.” 2014. Web. 11 Apr 2021.

Vancouver:

Mack PD. Sperm competition and the role of females in Drosophila melanogaster. [Internet] [Thesis]. University of Georgia; 2014. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10724/20381.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Mack PD. Sperm competition and the role of females in Drosophila melanogaster. [Thesis]. University of Georgia; 2014. Available from: http://hdl.handle.net/10724/20381

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


Virginia Tech

3. Dalton, Joseph C. Factors Important to the Efficiency of Artificial Insemination in Single-Ovulating and Superovulated Cattle.

Degree: PhD, Dairy Science, 1999, Virginia Tech

To identify factors important to the efficiency of artificial insemination in cattle, four studies were conducted. In the first study, the addition of cream to the inseminate was used in an attempt to increase accessory sperm number. On d 6 after insemination, 60 embryos were evaluated. The addition of cream to the inseminate had no effect on accessory sperm number. In the second study, cryopreserved semen of a marked bull (spermatozoa exhibiting a semi-flattened anterior head) was matched with semen from an unmarked bull (conventional sperm head shape) to determine competitively the effect of a deep uterine insemination on accessory sperm number. Forty embryos were recovered 6 d after insemination and the ratio of accessory sperm observed was different: 62:38 for unmarked semen in the uterine body and marked semen in the uterine horn, and 72:28 for unmarked semen in the uterine horn and marked semen in the uterine body (P < .05). In the third study, superovulated cows were utilized to determine the effect of artificial insemination time on fertilization status and accessory sperm number. Cows were inseminated once at 0 h (n=10), 12 h (n=10), or 24 h (n=10) after the first standing event. On d 6 after insemination, 529 embryos(ova) were recovered. Fertilization rates were 29% (0 h); 60% (12 h); and 81% (24 h)(P < .01). Percentages of embryos with accessory sperm were: 5 (0 h); 8 (12 h); and 41(24 h) (P < .01). In the fourth study, three experiments utilizing superovulated cows were conducted to provide a basis for distinguishing unfertilized ova from very early embryonic death. In Exp. 1, recovered d 6 unfertilized ova were classified morphologically as either: 1) typical, 2) satellite, or 3) fragmented. In Exp. 2, recovered d 6 unfertilized ova from the third study were classified morphologically, and typical ova were fixed. In Exp. 3, ultrastructural features of preovulatory, tubal-stage, and typical d 6 unfertilized ova were investigated. Preovulatory ova revealed normal ultrastructure; tubal-stage ova exhibited evidence of degeneration; typical d 6 ova were degenerated and contained no discernable organelles. The first three studies support the use of accessory sperm evaluation as an alternative measure of fertility. The final study provides a basis from which future embryologists may distinguish fertilization failure from very early embryonic death. Advisors/Committee Members: Saacke, Richard G. (committeechair), Nebel, Raymond L. (committee member), Bailey, Thomas L. (committee member), Lewis, Gregory S. (committee member), Grayson, Randolph Larry (committee member).

Subjects/Keywords: accessory sperm; artificial insemination; cattle; superovulation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Dalton, J. C. (1999). Factors Important to the Efficiency of Artificial Insemination in Single-Ovulating and Superovulated Cattle. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/27139

Chicago Manual of Style (16th Edition):

Dalton, Joseph C. “Factors Important to the Efficiency of Artificial Insemination in Single-Ovulating and Superovulated Cattle.” 1999. Doctoral Dissertation, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/27139.

MLA Handbook (7th Edition):

Dalton, Joseph C. “Factors Important to the Efficiency of Artificial Insemination in Single-Ovulating and Superovulated Cattle.” 1999. Web. 11 Apr 2021.

Vancouver:

Dalton JC. Factors Important to the Efficiency of Artificial Insemination in Single-Ovulating and Superovulated Cattle. [Internet] [Doctoral dissertation]. Virginia Tech; 1999. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/27139.

Council of Science Editors:

Dalton JC. Factors Important to the Efficiency of Artificial Insemination in Single-Ovulating and Superovulated Cattle. [Doctoral Dissertation]. Virginia Tech; 1999. Available from: http://hdl.handle.net/10919/27139

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