The objective of this study was to use fluorescent in situ hybridization (FISH) to determine if a skew in the sex ratio was present at the level of the bovine round spermatid. Paraffin embedded bovine testicular tissue obtained from biopsies were used to perform FISH, and the seminiferous tubules were examined. Our findings show that the skew does exist within the round spermatids. Analysis of variance on X- and Y-chromosome bearing round spermatids as affected by sex, slide, picture set, and tubule was performed. Sex showed that the variation in round spermatid sex ratio differed between slides (P = 0.0001). The interaction of sex by slide were indicated to be non-significant (P = 0.0815). Sex within tubule nested in slide showed a significant deviation in sex ratio (P = 0.0122). Picture set showed no significant difference in counts, confirming that the counts were consistent (P = 0.2096). A closer look at the data also showed a 10 to 30% variation in the number of seminiferous tubules with a significant skew per slide. Most the skew was toward the Y-chromosome, but a significant skew toward the X-chromosome was also seen. This skew toward the X-chromosome showed that the skew could be counteracted or reversed.
Meiotic drives have been shown to exist in other species. Meiotic drives are alleles with the ability to increase their probability of being transmitted to the next generation. Although we cannot prove that a meiotic drive exists in bovine, our findings agree with the meiotic drive principle. These drives push the sex ratio of the population in one direction. Modifiers attached to these drives can counteract or reverse the effect of the meiotic drive. Environmental factors such as crowding, brought on by intense group housing could also have an effect on the expression of these drives. Further investigation is necessary to completely understand these skews in sex ratio and what factors may affect it.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-07102006-185322 |
| Date | 11 July 2006 |
| Creators | Stout, Michael Alan |
| Contributors | Fakhri Al-Bagdadi, Cathleen Collett Williams, John E. Chandler |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-07102006-185322/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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