Three aspects of sexual reproduction and development of a Puerto Rican strain of Schistosoma mansoni in white mice were studied. It has long been known that the male in the genus Schistosoma is essential for the somatic and reproductive development of the female, but no critical study has been reported to date on whether or not the reverse is true. / In order to determine what influence, if any, the female may have on the development of male worms, somatic growth and reproductive development of males from bi- and unisexual infections were compared. No difference was noted between males of identical ages from bi- and unisexual infections (of 20 to 120 days) with respect to length, degree of reproductive development, and meiotic events. / The sequence of meiotic events in the male S. mansoni is typical of most diploid organisms: chromosome condensation, synapsis, and balanced distribution to the gametes. The mean chiasma frequency was 23.22 $\pm$ 1.4. This strain has, on the average 11.61 cross-overs or 1161 units of map lengths. / Light and transmission electron microscopy showed that the spermatozoa of Schistosomatium douthitti and Heterobilharzia americana conform to the "standard" digenean sperm morphology (filiform, with 2 axial complexes of the 9+1 microtubule arrangement), whereas the sperm of S. mansoni are more bulbous with one axoneme. S. douthitti and H. americana sperm have two free flagella that emerge posteriorly, whereas S. mansoni sperm has a single flagellum. / Source: Dissertation Abstracts International, Volume: 49-03, Section: B, page: 0604. / Major Professor: Robert B. Short. / Thesis (Ph.D.)--The Florida State University, 1987.

Caenorhabditis elegans spermatozoa are nonflagellated, ameboid cells that contain no F-actin yet are capable of crawling over solid surfaces. In this study, the role of cell surface membrane dynamics in locomotion were studied. Monoclonal antibodies against membrane proteins were generated and used to examine (1) the detailed pattern and mechanism of surface membrane movement, (2) the pattern and mechanism of insertion of new membrane components onto the spermatozoan surface, and (3) the effects of anti-cell surface protein antibodies on cell locomotion. I found that the general pattern of front-to-back membrane flow observed on other crawling metazoan cells also occurs on the pseudopod of C. elegans spermatozoa. Replacement of labelled membrane proteins lost to rearward flow occurs by a mechanism that inserts new protein onto the tips of numerous pseudopodial projections which contact the substrate during crawling, exactly where they are needed to expand the cell forward and create new sites of substrate adhesion. Membrane protein insertion occurs in the absence of cytoplasmic vesicles by a mechanism involving the post-translational, covalent attachment of lipid to the protein. Sperm do not crawl on naked glass, however, anti-cell surface antibodies immobilized on glass promote locomotion. This effect was concluded to be specific based, in part, on the ability of soluble antibody to stop locomotion in a concentration dependent fashion. / Source: Dissertation Abstracts International, Volume: 48-12, Section: B, page: 3478. / Thesis (Ph.D.)--The Florida State University, 1987.

Source: Dissertation Abstracts International, Volume: 37-06, Section: B, page: 2632. / Thesis (Ph.D.)--The Florida State University, 1976.

Source: Dissertation Abstracts International, Volume: 37-10, Section: B, page: 4824. / Thesis (Ph.D.)--The Florida State University, 1976.

Source: Dissertation Abstracts International, Volume: 39-11, Section: B, page: 5193. / Thesis (Ph.D.)--The Florida State University, 1978.

Source: Dissertation Abstracts International, Volume: 33-06, Section: B, page: 2483. / Thesis (Ph.D.)--The Florida State University, 1971.

Source: Dissertation Abstracts International, Volume: 33-07, Section: B, page: 2951. / Thesis (Ph.D.)--The Florida State University, 1972.

Source: Dissertation Abstracts International, Volume: 34-09, Section: B, page: 4223. / Thesis (Ph.D.)--The Florida State University, 1973.

Source: Dissertation Abstracts International, Volume: 28-03, Section: B, page: 0791. / Thesis (Ph.D.)--The Florida State University, 1967.

Reports in the literature have shown that sex ratios of adult schistosomes, in mammalian hosts, are usually biased toward males despite the finding that sex is determined (ZZ males, ZW females) in the zygote, giving the expectation of a 50:50 sex ratio for miracidia. The ability to identify the sex of Schistosoma mansoni larvae by examining interphase nuclei for W-chromatin (Liberatos and Short, 1983, J. Parasitol., 69:1084-1089) made possible the monitoring of sex ratios as the life cycle progressed from miracidia to adults. / The sex ratio of miracidia (within 1 hr after hatching) was 211 males:216 females, and did not differ significantly from 50:50. The adult sex ratio was biased toward males (3:1), and the bias was caused by greater male infectivity of miracidia for snails and cercariae for mice. A significantly higher percentage of male miracidia developed to cercarial production in unimiracidial infections (57 male, 34 female snail infections), and a significantly higher percentage of male cercariae developed to adulthood in mice (143 male, 79 female worms resulted from 900 male and 900 female cercariae). / No significant differences were found between male and female parasites for longevity of miracidia (about 10 hr) and cercariae (males 21.3 (+OR-) 5.75, females 25.0 (+OR-) 7.02 hr), prepatent periods of snail hosts (males 34 (+OR-) 2.92, females 33 (+OR-) 2.36 days), longevity of snail infections (males 96.6 (+OR-) 25.15, females 115.2 (+OR-) 82.43 days), and the number of cercariae produced (males 30,751.44 (+OR-) 18,064.33, females 34,083.00 (+OR-) 33,732.82 per snail lifetime). / Present results are of theoretical significance for theories of biased sex ratios, which at present cannot account for the male-biased ratio of S. mansoni. Present results also suggest that transmission models for schistosomiasis that assume a 50:50 sex ratio at all stages of the life cycle should be reassessed. / Source: Dissertation Abstracts International, Volume: 47-05, Section: B, page: 1827. / Thesis (Ph.D.)--The Florida State University, 1986.