Oviductal Sperm Storage Research Articles

Identification of a sperm cell attribute responsible for subfertility of roosters homozygous for the rose comb allele.

Fertility, sperm metabolism, sperm filling of oviductal sperm storage tubules (SST), and sperm motility were compared in subfertile roosters homozygous for the rose comb allele (R/R) and fertile controls (r/r or R/r males). As expected, fertility of R/R males was less than that of controls (p < 0.0001). The metabolic rate of spermatozoa from R/R males was also lower than that of controls (p < 0.05). Likewise, filling of SST in vivo was lower (p < 0.0001) for spermatozoa from R/R males than for control spermatozoa. However, in vitro filling of SST was not different between genotypes (p > 0.05). Motility of spermatozoa from R/R males was less than that of controls (p < 0.001) as determined by an objective spectrophotometric assay. Previous researchers have concluded that subfertility associated with homozygosity for the rose comb allele is attributable to a sperm-specific phenomenon. However, the cellular mechanism(s) responsible for the subfertile status were not defined. In contrast to previous researchers, we have demonstrated that subfertility of R/R males is explicable in terms of reduced sperm transport through the hen's vagina; reduced sperm motility appears to be the major contributing factor.

Sperm Storage and Transport Following Natural Mating and Artificial Insemination

Recent observations in turkey and chicken hens show that sperm storage in both species is a highly inefficient process. After artificial insemination (AI), less than 1% of spermatozoa inseminated are selected for transport to and enter the sperm storage tubules (SST). It has been shown that the sperm selection process is orchestrated within the vagina and not at the level of the SST. At least two mechanisms are involved in the selection of spermatozoa fit for sperm storage, one being mechanical (motility) and the other biochemical in nature (sperm-vaginal mucosa interactions). Furthermore, it was also observed that the sperm storage efficiency in the chicken is dependent upon the logarithm of the number of spermatozoa inseminated. From a practical standpoint, inseminations performed frequently with a moderate number of spermatozoa should be more efficient than inseminations performed with higher doses at longer intervals.Maximal filling of the SST of hens in egg production requires only 1 day for the chicken and 2 days for the turkey. By contrast, the release of sperm from the SST is about seven times faster in the chicken than the turkey hen. The efficiency of oviducal sperm storage is related to a number of factors including age of the hen, stage of the ovulatory cycle when inseminated, and, in the turkey, if the hen was inseminated before or after the onset of egg production.Two different categories should be considered among factors that affect sperm survival in vivo. 1) Factors affecting sperm storage. These factors, acting in the vaginal portion of the oviduct, regulate the migration of spermatozoa up to the SST by increasing (e.g., short intervals between oviposition and AI) or decreasing (e.g., sperm migration in prelaying hens) the barrier effect of the vagina. 2) Factors affecting sperm release. In chicken hens, the hen’s age does not impair the sperm storage efficiency but rather increases the rate of release of spermatozoa, thus contributing to a shorter duration of fertility.

Oviducal sperm storage in poultry: a review.

Reproduction, Fertility and Development is an international journal publishing original research , review and comment in the fields of reproduction and developmental biology in humans, domestic animals and wildlife

Factors affecting oviductal sperm storage in domestic fowl following artificial insemination

The objective of this work was to investigate the effects of the type and age of the hen, number of spermatozoa inseminated, and time after insemination on the percentage of sperm storage tubules (SST) containing spermatozoa in domestic fowl. One hundred and thirty-nine layer type and 145 broiler type hens were inseminated at 31 or 59 weeks of age with either 60 × 10 6 or 240 × 10 6 spermatozoa. Hens were killed 1 and 6 h, 2, 4, 7, 14 and 21 days following insemination and their oviduct prepared for histology. Factors affecting percent sections of SST with spermatozoa were mainly the time after insemination and the type of hens and, to a lesser extent, the age and the dose inseminated. Percent SST sections with spermatozoa between homologous groups increased with doses of semen but was not proportional to the number of spermatozoa deposited intravaginally. In most situations, the highest percentages of SST sections containing spermatozoa (from 12 to 54%) were observed only 2 days after insemination. This indicates that the lumen of the oviduct may play the role of a short-term storage area for spermatozoa in the oviduct of birds.

Influence of Neuraminidase on Fertility and on Sperm Storage in the Hen's Oviduct

Preinsemination incubation of semen with neuraminidase (4 IU/2 × 109 spermatozoa) significantly reduced fertility in one out of two trials. No differences were observed in fertility between semen treated with 4 versus 8 or 4 versus 16 IU of neuraminidase in Trials 1 or 2. All three levels of neuraminidase (4, 8, or 16 IU) removed the same amount (about 45%) of the bound sialic acids from spermatozoa during incubation. The removal of sialic acid from spermatozoa had a slight but nonsignificant affect on sperm storage within the uterovaginal (UV) sperm-host glands. Hens inseminated with neuraminidase-treated spermatozoa had decreased numbers of full and partially full UV sperm-host glands and increased numbers of empty glands, compared to hens inseminated with untreated but incubated spermatozoa. In the present study, reduced fertility resulting from the treatment of spermatozoa with neuraminidase from Clostridium perfringens indicates the desirability of exploring the use of other neuraminidases to see whether a correlation exists between the amount of sialic acid removed from spermatozoa and their subsequent fertility.

Histology and histochemistry of the oviductal sperm storage pockets of the agamid lizard Calotes versicolor.

Some reptiles are known to possess sperm storage in the female genital tract. Examination of the oviduct of the lizard Calotes versicolor shows the presence of sperm in storage pockets of the uterovaginal region throughout the reproductive cycle. Histochemical studies indicate that the epithelium of these pockets resembles the local oviductal epithelium and that a considerable amount of activity of steroidogenic and metabolic enzymes exists.

Physiological changes in fowl and turkey spermatozoa during in vitro storage.

1. Although early work on semen storage has been rather empirical in approach, only basic research can provide a framework of biological mechanisms from which improvements in the techniques of cryopreservation and liquid semen storage can progress logically. 2. A major drawback in this work has been the lack of adequate tests for quantitating and differentiating aspects of 'fertility'. 3. Basic research has now provided techniques for assessing: sperm fertilising ability in terms of numbers of fertile eggs; the efficiency of hens' oviducts at accepting and retaining spermatozoa, and sperm 'quality' as motility, metabolism and plasma membrane patency. 4. These techniques may be used for a more critical assessment of the effects of both cryopreservation and liquid semen storage on sperm function, although the integrity of sperm surface proteins may be a more sensitive variable which has yet to be measured. 5. Further improvements in sperm cryopreservation technology are best approached through an understanding of the fundamental cellular and molecular changes which take place during freezing; thus far little is known of such changes in avian spermatozoa. 6. The ideal milieu for maintaining spermatozoa in liquid semen storage should mimic the environment of the oviducal sperm storage tubules; elucidation of the factors involved in progressing steadily.

Effect of the ovulatory cycle on oviductal sperm storage in the domestic fowl

Anovulatory domestic hens (pregnant mare serum-treated) and normally cyclic domestic hens were artificially inseminated with 0.034 ml of pooled semen. A subsequent microscopic assessment of the uterovaginal sperm storage glands on days 1, 3, 6, 9 and 12 post-insemination indicated that the sperm glands emptied over time in the normally cyclic hens, but not in the anovulatory hens. The data suggest that events associated with ovulation and/or oviposition are important to the sperm gland emptying process.

Effect of Insemination Intervals on Oviducal Sperm Storage in Turkeys , ,

Filling and emptying of sperm storage sites of the turkey oviduct were studied using tandem inseminations with semen from bronze and white males. Fertility was better among hens inseminated at weekly intervals than those inseminated at biweekly intervals. The rate of gland filling and emptying was unaffected by weekly and biweekly insemination intervals. However, gland filling and emptying were affected when the birds were inseminated early in a reproductive cycle, and stratification of spermatozoa occurred within the sperm-host glands. Stratification may have occurred to a lesser degree late in the reproductive cycle. It is suggested that sperm storage glands fill and empty at the same rates early and late in a breeding cycle, but fewer glands contain spermatozoa in the latter part of the season, resulting in a decreased fertility.