Migration of Y-Bearing Human Spermatozoa in Cervical Mucus

Rohde, W; Porstmann, T; Dörner, G

doi:10.1530/jrf.0.0330167

Cited by 34 publications

(14 citation statements)

References 6 publications

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“…These combined data suggest that preconceptional mechanisms (versus reproductive failure) became increasingly important in producing the sex ratio adjustment in response to January rain. (Examples of preconceptional mechanisms from the literature include: selective mortality of X-versus Y-bearing sperm; or timing mating relative to ovulation to take advantage of faster swimming, shorter-lived Y-bearing sperm; Rohde et al 1973). Greater emphasis on preconceptional mechanisms (versus sex-specific reproductive failure) as the ecological year progressed also made adaptive sense because survival conditions remained poor until the end of the year (Fig.…”

Section: Discussionmentioning

confidence: 99%

Baboons adjust secondary sex ratio in response to predictors of sex-specific offspring survival

Wasser

Norton

1993

Behav Ecol Sociobiol

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Section: Discussionmentioning

confidence: 99%

Baboons adjust secondary sex ratio in response to predictors of sex-specific offspring survival

Wasser

Norton

1993

Behav Ecol Sociobiol

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“…It is possible that X and Y chromosome-bearing spermatozoa have many physiological differences due to differences in motility [29], timing of capacitation [30] and survival time [31] in the bovine reproductive tract. These differences would favor X chromosomebearing spermatozoa when insemination is performed long before ovulation.…”

Section: Discussionmentioning

confidence: 99%

Relationships among Estrous Behavior, Superovulatory Response and Grade 1 Embryo Sex Ratio in Superovulated Holstein Heifers

Ideta

Hayama

Urakawa

et al. 2007

Journal of Reproduction and Development

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Abstract. Abstract. In this study, we first attempted to determine whether the timing of artificial insemination affects the sex ratio of seven-day-old embryos in superovulated Holstein heifers. The superovulatory treatment consisted of eight decreasing doses of FSH for 4 days and 2 doses of PGF2α given with the last two doses of FSH. The superovulated heifers were given a GnRH analogue 48 h after the first PGF2α treatment and were artificially inseminated 48 h (n=10) or 56 h (n=8) after the first PGF2α treatment. There were no significant differences in the percentages of unfertilized ova and transferable embryos (grades 1 to 3) between the two groups. The proportions of female grade 1 embryos did not significantly differ from the expected ratio of 50:50 (49.3% at 48 h and 52.5% at 56 h). We then compared the estrous behavior and superovulatory responses of the heifers with a proportion of female embryos of 50% or less (n=7, Low group) to those of the heifers with a proportion of female embryos of more than 50% (n=9, High group). The Low group had a longer duration of estrus and a higher superovulatory response than the High group. These findings offer little encouragement for prediction of the population of female embryos collected from superovulated heifers. Further studies are necessary to evaluate to what degree maternal hormone levels are related to estrus duration and sex ratio. Key words: Estrous behavior, Sex ratio, Superovulation, Superovulatory response (J. Reprod. Dev. 53: [1015][1016][1017][1018][1019][1020][1021] 2007) he dairy and beef industries mainly use female or male animals, respectively. Numerous efforts have been directed toward developing procedures to skew the sex of offspring [1][2][3]; however, it is difficult to draw clear conclusions from the literature, as different laboratories have reported conflicting results under similar conditions. Significant enrichment of X chromosome-bearing spermatozoa has only been demonstrated by sex selection of spermatozoa based on chromatin differences (cell sorting by flow cytometry) [4]; however, this procedure is not widely used due to the cost of the equipment and the limitations in relation to sorting rate.On the other hand, the sex ratio of offspring has been altered for several species by varying the timing of insemination, such as in humans [5,6], hamsters [7,8], mice [9] and sheep [10]. In cattle, some researchers have shown that varying the timing of artificial insemination (AI) does not influence embryo sex ratio [11,12]. The overall sex ratio of bovine embryos produced in vivo and in vitro does not differ from the expected ratio of 50:50 [13][14][15].

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“…One possible mechanism is based on differences in the behavior of X-and Y-bearing spermatozoa. Rohde et al (1973) report that human Xsperm tend to live longer than their Y-bearing counterparts, but that Y-sperm tend to swim faster. If the same were true of golden hamster spermatozoa, then matings that occurred before ovulation should produce an excess of females, because Xsperm would do better than Y-sperm at surviving to the time of ovulation, while matings that occurred after ovulation should produce an excess of males, because Y-sperm would generally be the first to arrive at the waiting ova.…”

Section: Discussionmentioning

confidence: 99%

Litter sex ratios in the golden hamster vary with time of mating and litter size and are not binomially distributed

Huck

Seger

Lisk

1990

Behav Ecol Sociobiol

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Pregnancy rates, litter sizes, and litter sex ratios vary strongly with the time in the estrous cycle at which female golden hamsters (Mesocricetus auratus) are mated. Early matings tend to produce relatively high pregnancy rates, large litters, and female-biased sex ratios, while late matings tend to produce low pregnancy rates, small litters, and male-biased sex ratios. Time of mating and litter size are therefore correlated, but each appears to have an independent effect on litter sex ratio: time of mating and sex ratio are positively correlated, holding litter size constant, while litter size and sex ratio are negatively correlated, holding time of mating constant. At each litter size greater than two, the variance of litter sex ratios is less than the binomial variance expected on the hypotheses of independent sampling with a constant probability of producing a male. The main features of the distribution of litter sex ratios can be generated from a causal model in which different probabilities of producing a male apply to "early" and "late" conceptions within each litter. The relationship between litter size and mean litter sex ratio is potentially consistent with several different models for the evolution of adaptive sex-ratio variation.

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Migration of Y-Bearing Human Spermatozoa in Cervical Mucus

Cited by 34 publications

References 6 publications

Baboons adjust secondary sex ratio in response to predictors of sex-specific offspring survival

Baboons adjust secondary sex ratio in response to predictors of sex-specific offspring survival

Relationships among Estrous Behavior, Superovulatory Response and Grade 1 Embryo Sex Ratio in Superovulated Holstein Heifers

Litter sex ratios in the golden hamster vary with time of mating and litter size and are not binomially distributed

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