The mRNA for zona pellucida proteins B1, C and D in two genetic lines of turkey hens that differ in fertility

The avian inner perivitelline layer (IPVL) contains zona pellucida protein-B1 (ZPB1), zona pellucida protein-C (ZPC) and zona pellucida protein-D (ZPD). These three proteins may be involved in sperm binding to the IPVL. ZPB1 is produced by the liver and transported to the developing preovulatory follicle, while ZPC and ZPD are synthesized and secreted by the granulosa cells of the preovulatory follicle. The mRNA of ZPB1, ZPC, and ZPD was investigated in two lines of turkey hens selected for over 40 generations for either increased egg production (E line) or increased body weight (F line). Total RNA was extracted from the liver and from 1cm(2) sections of the granulosa layer around the germinal disc and a nongerminal disc area of the F(1) and F(2) follicles of hens from each genetic line. Northern analysis was performed using chicken cDNA probes for all three ZP proteins. Hepatic mRNA for ZPB1 was greater (P<0.05) in turkey hens from the E line than the F line. Although, there was no difference in ZPC mRNA between the germinal disc and nongerminal disc region of the two largest follicles in E line hens, ZPC mRNA was greater in the nongerminal disc region compared to the germinal disc region in the two largest follicles obtained from the F line hens. There were no differences in ZPD mRNA between the germinal disc and nongerminal disc regions of the F(1) and F(2) follicles for either genetic line. The results suggest that the greater rates of fertility previously observed in eggs from the E line hens compared with the F line of hens may be related to differential amounts of the potential sperm binding proteins ZPB1 and ZPC.     

Preferential attachment of cock spermatozoa to the perivitelline layer directly over the germinal disc of the hen's ovum.

In vitro incubation of cock spermatozoa with perivitelline layer (PL) from recently ovulated ova of the hen resulted in binding of spermatozoa to the PL and activation of the acrosome reaction. A simple quantitative technique was developed for assessing these events. Following incubation of the PL (0.5 cm2 sections) with spermatozoa, the PL section was rinsed and stained with Schiff's reagent. Microscopic examination revealed holes in the PL that were assumed to be sites of spermatozoa penetration. Utilizing this technique, a correlation was demonstrated between sperm concentration and the number of spermatozoa attaching to the PL and undergoing an acrosome reaction. Pre-treatment of spermatozoa with solubilized PL inhibited spermatozoa binding to pieces of intact PL. The PL overlying the germinal disc and a similarly sized section of PL from another area of the ovum were removed and incubated separately with spermatozoa (1 x 10(5) sperm/100 microliters). Spermatozoa showed preferential attachment and digestion of the PL from the germinal disc area (809 sperm/mm2) as compared to PL from other areas of the ovum (608 sperm/mm2). Spermatozoa attached to the PL in a circular, doughnut-shaped fashion in the area directly over the germinal disc.     

Species specificity in avian sperm:perivitelline interaction

The interaction of chicken spermatozoa with the inner perivitelline layer from different avian species in vitro during a 5 min co-incubation was measured as the number of points of hydrolysis produced per unit area of inner perivitelline layer. The average degree of interaction, as a proportion of that between chicken spermatozoa and their homologous inner perivitelline layer, was: equal to or greater than 100% within Galliformes (chicken, turkey, quail, pheasant, peafowl and guineafowl); 44% within Anseriformes (goose, duck); and less than 30% in Passeriformes (Zebra Finch) and Columbiformes (collared-dove). The homologue of the putative chicken sperm-binding proteins, chicken ZP1 and ZP3, were identified by Western blotting with anti-chicken ZP1/ZP3 antibody in the perivitelline layers of all species. The functional cross-reactivity between chicken spermatozoa and heterologous inner perivitelline layer appeared to be linked to known phylogenetic distance between the species, although it was not related to the relative affinity of the different ZP3 homologues for anti-chicken ZP3. This work demonstrates that sperm interaction with the egg investment does not represent such a stringent species-specific barrier in birds as it does in mammals and marine invertebrates. This may be a factor in the frequency of hybrid production in birds.     

Assessment of fresh and stored duck spermatozoa quality via in vitro sperm-egg interaction assay

An in vitro sperm-egg interaction assay was used to measue the quality of duck spermatozoa in fresh and stored semen. The inner perivitelline layer (IPVL), which had been separated from laid duck eggs, was incubated with spermatozoa in vitro. The number of points of sperm hydrolysis in the IPVL in vitro was logarithmically correlated with the fertility of the eggs laid by inseminated females, for both fresh semen (r = 0.85, P < 0.001) and stored semen at 5 degrees C for 24 h (r = 0.84, P < 0.001). After semen storage, the ability of spermatozoa to hydrolyze the IPVL decreased by 67.4% compared with the values for fresh semen, whereas egg fertility and sperm motility decreased by 47.8% and 15.2%, respectively. These results suggest that the in vitro sperm-egg interaction assay accurately reflects the fertilizing ability of fresh and stored duck spermatozoa and detects spermatozoal damage due to semen storage more sensitively than motility or fertility tests.     

Characterization of the sperm-associated body and its role in the fertilization of the chicken Gallus domesticus

The present paper aimed to characterize the substance forming the sperm-associated body (SB), to find its producing sites, and to show its functions in the fertilization of chicken. The SB was found both in between the inner and outer layers of vitelline membranes around eggs and in the oviductal infundibulum. Material from which the SB is constructed (SB substance) was isolated from the vitelline membranes. It was a hydrophobic protein with a molecular size of 570 kDa. X-ray microanalysis detected calcium in the aggregates of the SB substance. Immunofluorescence and immunoelectron microscopy showed that the substance was produced in secretory cells in the luminal epithelium of the oviductal infundibulum and was provided to the egg on and in its vitelline membrane. During incubation, the SB substance bound with spermatozoa in the posterior portion of their flagella. Holes and disks were found in the vitelline membranes of fertile eggs at a ratio of 1: 19-24. Over 94% of the holes were accompanied by SB. The presence of SB is necessary for fertile spermatozoa to make holes in the membrane and to enter the fertile egg.     

Sperm-egg interaction is mediated by a sperm-associated body in quail

The present study describes the holes in the inner vitelline membrane of fertile eggs of the quail Coturnix japonica, which remain after the spermatozoa pass through. It was shown that the light-microscopically observable 'holes' correspond mostly to electron-microscopically defined 'disks', and, to a lesser extent (about 5%), real holes. Immunofluorescent staining of the vitelline membranes with an antiquail ZPC antiserum was used to discriminate the holes from the disks light-microscopically. Over 96% of holes were accompanied by calcium-coated sperm-associated bodies, indicating a close relationship between the two. There was no preferential localization of the disks, holes or sperm-associated bodies in the vitelline membrane around the egg. The sperm-associated bodies bound with the spermatozoa at the posterior end of sperm flagella. Incubation of the inner vitelline membranes, isolated from the largest follicles, with spermatozoa resulted in production only of the disks, whereas the holes (about 9%) were produced when the sperm-associated bodies were added to the system. It was suggested that the sperm-associated bodies assist fertile spermatozoa in binding to the inner vitelline membrane, making holes in the membrane and passing through them in fertile eggs.     

The rôle of the spermathecal gland of the boll weevil,Anthonomus grandis

Spermatozoa were relatively inactive and did not enter the spermatheca of female boll weevils, Anthonomus grandis, whose spermathecal glands were removed as teneral adults. However, these females were able to lay fertile eggs for a 2 week period. When the spermathecal gland was removed from older females, spermathecal filling occurred, and although the spermatozoa retained their fertilizing capacity for extended periods, spermathecal emptying did not occur. Spermatozoa gradually lost their motility and fertilizing capacity, indicating that spermathecal secretions are effective in very small amounts. Spermatozoa were not activated by any of the materials contained in the normal male ejaculate. These materials alone did not effect spermathecal filling nor were they capable of maintaining the fertilizing capacity of the spermatozoa for very long. Sperm economy is low with less than 1 fertile egg laid per 100 spermatozoa used.     

Egg Fertility in Domestic Fowl Gallus gallus domesticusas a Function of the Yolk Surface Area

The increase of egg mass and reliable decrease of egg fertility were observed when the mass surface area of yolk (egg) increased. The results obtained suggest that, in addition to the number of viable spermatozoa penetrating across the perivitelline membrane within 15–20 min after ovulation, the probability of fertilization depends on the area of egg surface, which approximately corresponds to the area of perivitelline membrane. Apparently, the ratio of receptors numbers and spermatozoa, which contact with them on the germ disc surface, to their number on the non-germ zone decreases with the increase of yolk size. The fertility depression associated with the increased area of perivitelline membrane suggests that the egg yolk size is one of the factors of fertility of the female gametes in terms of both egg content variability and aging.     

Quantification of spermatozoa in the sperm-storage tubules of turkey hens and the relation to sperm numbers in the perivitelline layer of eggs

This study was conducted to determine the number of spermatozoa residing in the oviduct sperm-storage tubules (SST) and the relationship between these numbers and the number of spermatozoa embedded in the perivitelline layer of oviductal eggs after a single insemination of 200 x 10(6) spermatozoa. The SST of hens inseminated within one week before the expected onset of egg production were filled faster (4 h vs. 2 days) and possessed more spermatozoa (4.1 vs. 2.0 x 10(6)) than the SST of hens inseminated after the onset of egg production. Furthermore, for hens in egg production, significantly fewer spermatozoa were recovered from the SST if the hen was inseminated within 2 h before or after oviposition than if inseminated more than 2 h before or after the oviposition. There was a strong positive correlation between the number of spermatozoa in the SST and the number of spermatozoa embedded in the perivitelline layer of the oviductal eggs (r = 0.85, p less than 0.01). These data show that the population of spermatozoa actually accepted by the SST is quite small relative to the number of spermatozoa inseminated and that maximum sperm-storage is achieved when the hen is inseminated just prior to the onset of egg production. It is suggested that the sperm-storage capacity of the oviduct and the quality of the semen sample can be estimated on the basis of numbers of spermatozoa embedded in the egg perivitelline layer.     

Repeated inseminations required for natural fertility in a wild bird population

In most bird species, pairs copulate many times before egg laying. The exact function of repeated inseminations (i.e. successful copulations) is unknown, but several suggestions have been made. We tested the hypothesis that repeated inseminations are required to ensure fertilization of eggs, by using an experimental method where free-ranging male collared flycatchers (Ficedula albicollis) were prevented from inseminating their mates. We show that egg fertility was lower when females had not copulated during the studied part of their fertile period. By counting sperm on the inner perivitelline layer of eggs, we estimated that a minimum of 86 sperm must reach the site of fertilization to ensure average fertility. Using the timing of inseminations and the numbers of sperm on successive eggs, we show that repeated copulations are necessary to achieve an average rate of fertilization of a single clutch. Our results thus provide evidence that repeated inseminations function to ensure fertilization success. We discuss possible constraints on sperm production and utilization that may have contributed to this pattern.     

Eggs fertilizability in domestic hens Gallus gallus domesticus as a function of the yolk surface area

The increase of egg mass and reliable decrease of egg fertilizability were observed when the mass surface area of yolk (egg) increased. The results obtained suggest that, in addition to the number of viable spermatozoa penetrating across the perivitelline membrane within 15-20 min after ovulation, the probability of fertilization depends on the area of egg surface, which approximately corresponds to the area of perivitelline membrane. Apparently, the ratio of receptors' numbers and spermatozoa, which contact with them on the germ disc surface, to their number on the rest part of perivitelline membrane decreases with the increase of yolk size. The decreased egg fertilizability concomitant with the increased area of perivitelline membrane suggests that the egg size is one of the factors of fertility of the female gametes as concerns both variability of the egg composition and age.     

Age effect of broiler breeders on fertility and sperm penetration of the perivitelline layer of the ovum

The objective of this study was to determine the age effect of a broiler breeder flock on duration of fertility and number of spermatozoa penetrating the perivitelline layer overlying the germinal disc (SP/mm(2) GDIPVL). Moreover, in the second half of the flock's reproductive life, the effect of using ejaculates of young roosters (CA2) in artificial insemination (AI) on the above parameters of fertility was estimated. The commercial flock of broiler breeder hens (n = 100) was inseminated six times from 31 to 62 weeks of age. Additional inseminations, with ejaculates of roosters aged 31 and 36 weeks (CA2), were performed at 56 and 62 weeks of age. AI was performed during two consecutive days (D0 and D1) with an insemination dose of 125 x 10(6) spermatozoa/0.06 ml containing pooled ejaculates. The following parameters were studied: the effective and maximum duration of fertility (De and Dm), percent of fertility on different days after AI (FD10, FD15 and FD20), indices of duration of sperm penetration (DSP, SP < or = 3/GDIPVL), SP/mm(2) GDIPVL in eggs laid on successive days after insemination of hens at different age, and correlations between some fertility indices. Both for De and Dm, the highest values were noted after AI of the layers at 36 weeks of age (14.8 +/- 0.49 and 17.4 +/- 0.46 days, respectively), which were about 2 days longer than at 56 weeks. All fertility indices decreased gradually with age, starting from AI at peak egg production (31-36 weeks of age), while the use of ejaculates from CA2 did not help to increase them significantly. Correlation coefficients between SP/mm(2) GDIPVL and the other fertility indices were positive and highest for eggs laid on D3. It is concluded that high De values can be obtained from broiler breeders in adequate environmental and technological conditions of AI. It is suggested that the age-related decrease in fertility is more pronounced in females, in which the efficiency of sperm storage tubules decreases. The present fertility indices indicate the possibility of lengthening AI intervals, especially at peak egg production.     

Observations on egg production by Toxocara pteropodis

Studies in juvenile Pteropus poliocephalus showed an average daily egg production by Toxocara pteropodis of 25,000 per female, with concentrations of up to 16,000 epg. regardless of whether eggs were fertile or infertile. Production commenced as early as 35 and as late as 48 days post-partum and rose to plateau average levels over about 10 days. For 23 days one bat passed infertile eggs which, over 2 days, were then replaced completely by fertile eggs. The implicit delay in maturation of a male nematode suggests that transmammary passage of larvae to suckling bats may persist for at least 3 weeks. Patency was terminated by the spontaneous expulsion of worms. If male worms were lost first, the egg output converted from fertile to 100% infertile within 48 h and the females were devoid of spermatozoa, suggesting that T. pteropodis copulate at least once daily. In prolonged infections, worm fecundity and egg fertility diminished, so that females with stored spermatozoa were producing mixtures of fertile and infertile eggs.     

Effect of gamma-radiation on fowl sperm function in vitro and in vivo

Doses of up to 300 Gy of ionizing radiation had little effect on fowl sperm morphology, ATP content and motility when measured in vitro. Fertility of eggs from hens inseminated with spermatozoa receiving 50 Gy, in terms of post-oviducal development, was less than 4%. However, 35% appeared 'fertile' by macroscopic examination of the germinal disc of unincubated eggs. These contained few embryonic cells, although the vitelline membrane contained many trapped spermatozoa. After doses of 100 Gy or more, inseminated spermatozoa were not found in the vitelline membrane and no fertile or apparently fertile eggs were produced; nor did such spermatozoa enter the utero-vaginal sperm-host glands. Genetic transformation using fowl spermatozoa irradiated with doses in excess of 100 Gy appears to be an unlikely prospect.     

Preliminary results of hemizona assay (HZA) as a fertility test for canine spermatozoa

The Hemizona assay (HZA) is considered to be an effective test for predicting the fertilizing potential of spermatozoa. It is a functional test that distinguishes the zona-binding capacity of spermatozoa from fertile and infertile males. The objective of this study was to validate the HZA for canine spermatozoa, as a test for diagnosing canine male fertility status. Various parameters that affect binding capacity were examined: the presence of an adequate number of capacitated and motile spermatozoa for an HZA, the influence of fertility status, sperm-binding variability within fertile dogs over 60 d, variability in sperm-binding capacity of different oocytes, the lower limit number of spermatozoa binding to a zona from the fertile control, and evaluation of HZI to determine the fertilizing capacity of spermatozoa. Hemizonae were obtained from frozen oocytes of spayed bitches. The oocytes were manually cut into nearly equal halves. Spermatozoa were capacitated by swim-up and 1 h incubation at 37 degrees C in modified Ham's F10 medium. Spermatozoa and hemizonae were co-incubated in 100-microL drops at 37 degrees C for 1 h. Spermatozoa from 7 fertile and 3 infertile dogs were used for this study. The optimal sperm concentration for hemizona insemination was 1 x 10(6)/mL capacitated and motile spermatozoa. A significant difference (P < 0.001) was found the number of tightly zonabound spermatozoa between fertile and infertile dogs. Although there was a small difference in zona binding capacity between ejaculates of the same fertile dog (44 +/- 18.24), the main cause for the difference mentioned above was that of poor zona pellucida-binding capacity of spermatozoa from infertile dogs. We found a maximum of 14.28% bad oocytes when we compared sperm samples from 3 fertile and 3 infertile dogs in 56 HZA replicates. To avoid the effect of bad zona on sperm binding we calculated 37 (95% CI) bound spermatozoa from infertile dogs in 56 replicates. Thus, an HZA experiment in which a control dog had < 37 zona bound spermatozoa was repeated. Based on a minimum of 37 bound spermatozoa for fertile males (controls), a differential zona-binding capacity and hemizona index (HZI) between fertile and infertile dogs and between 2 fertile dogs was determined. The binding differential between fertile and infertile dogs was 64.92 +/- 24.29, while between 2 fertile dogs it was 22.38 +/- 10.02 (P < 0.001). According to the HZI values, a value equal to or less than 41.11 indicated an infertile test dog, while an HZI value equal to or greater than 57.95 indicated a fertile test dog. Any value between these two could indicate either fertility or infertility. The evaluation of fertilizing potential of spermatozoa can be improved using the HZA protocols described above.     

Gametes and fertilization in the Chinese hamster

Freshly ovulated eggs are each surrounded by a compact cumulus oophorus. The overall diameter of the normal egg (including the zona pellucida) is about 100 μm. Cumulus cells, particularly those near the egg, are arranged redially in a viscous noncellular matrix. The spermatozoon is about 250 μm in length. The head a large acrosome, changes in which can be readily examined with the light (phase- contrast) microsope. When exposed to physiological salt solutions, testicular spermatozoa either were motionless or flexed the posterior half of their tails slowly. Spermatozoa from the caput epididymis were highly motile, flexing the entire tail. A few of them moved progressively. Mature spermatozoa from the vas deferens were highly motile and moved either straightforward or in a circle. They vibrated their tails stiffly without flexing them. In normally mated females, fertilization began sometime between 2 and 3 h after ovulation and was completed within the next 4 to 5 h. Spermatozoa swimming in the ampullary fluid or within the cumulus oophorus about the time of fertilization flexed the anterior half (which roughly corresponds to the midpieac region) of their tails. This peculiar movement may be homologous to the so-called “hyperactivation” of spermatozoa as reported in several other mammalian species. Actively motile spermatozoa within the cumulus or no the zona pellucida had either modified (“collapsed”) or no acrosomal caps. The sperm head usually passed verticually or nearly through the zona, but the path was oblique in some instances. In 54% of the recently fertilized eggs examined, the entire length of the sperm tail was within the perivitelline space; in the other 46% of the eggs varying lenghts of the tail remined the perivitelline space, the tails were extruded from the vitellus of many eggs even before the eggs began their first cleavage. When unfertilized eggs in the cumulus oophorus were inseminated with vas deferens spermatozoa in a modified Tyrode's solution (m-TALP), about 80% of them were ferrtilized by 4–6 h after insemination. The vast majority were monospermic. When eggs were freed from the cumulus prior to insemination, none were fertilized, suggesting that the cumulus cells or their matrix assisted capacitation and/or the acrosome reaction of the spermatozoa under the in vitro conditions employed. No eggs were fertilized by the testicular or caput epididymal spermatozoa regardless of the presence or absence of cumulus oophorus around the eggs at the time of insemination.     

日本鳗鲡精卵的超微结构以及受精过程观察

通过扫描电镜和透射电镜对经人工催产获得的日本鳗鲡(Anguilla japonica)精子、卵膜的超微结构以及受精过程进行了观察。实验观察到,除一般硬骨鱼类的精子特性外,日本鳗鲡精子有其独特的结构。精子头部为不规则的梨形,有背腹面之分。一个巨大的球形线粒体位于头部顶端。精子中段向后伸出一支根,支根位于袖套腔外精子的背侧,前端向精子头部线粒体方向延伸,支根的微管结构为"8+2"结构,并在精子入卵过程中起到切断鞭毛的作用。精子的尾部由鞭毛和鞭毛末端的结组成。鞭毛横切面呈圆形,无侧鳍,鞭毛微管结构为"9+0"结构。受精卵的整个表面密布着无规律延伸的脊、脊包围形成的窝和窝中的孔所组成的脊孔复合体,但无典型特征的受精孔。受精卵超薄切片观察发现,日本鳗鲡卵膜分为外层壳膜和内层卵黄膜。壳膜与卵黄膜间为卵周隙。壳膜只观察到放射带,未见透明带。放射带可分为三个亚层:最外层为脊孔复合体的脊,中间层为皱纹层,最内层为致密的平滑层。脊孔复合体的孔横穿整个放射带,在放射带内层形成一个乳突状结构。日本鳗鲡的卵膜不仅具有保护卵子的作用,而且还参与了受精。实验还通过扫描电镜观察了日本鳗鲡精子的入卵过程。观察结果认为:日本鳗鲡精子入卵过程可分为卵膜对精子的吸引、精子对卵膜的锚定、精核的进入和孔封闭等4个阶段。但由于研究只观察到受精过程中日本鳗鲡精子和卵膜的形态变化,因此对精子穿过卵膜的方式和特征等尚需做进一步的研究。整个受精过程为1min30s左右。此外,研究还探讨了日本鳗鲡精子结构的特殊性和受精过程的特殊性,为进一步突破日本鳗鲡人工育苗技术提供了理论依据。       

Sperm–egg penetration assay assessment of the contraceptive effects of glycerol and egg yolk in rooster sperm diluents

Glycerol (GLY) and egg yolk (EY) are good cryoprotectants of avian and mammalian sperm, but in birds, they strongly inhibit the eventual fertilization of ova. Using the sperm penetration (SP-holes) assay and fertility trials, the present study investigates (1) the possible mechanism by which this contraceptive effect occurs in chickens and (2) the maximum concentrations of GLY and EY tolerated by fresh rooster sperm. Seventy Black-Barred Andaluza hens (five per treatment) were inseminated four times (twice per week) with 0.1 mL of fresh semen from roosters of the same breed diluted 1:1 (v:v) with Lake and Ravie medium containing different concentrations of GLY or EY. No adverse effects on acrosome integrity, sperm motility, or viability were seen with any concentration of GLY or EY. The number of SP-holes on perivitelline layer samples taken from above the germinal disc became progressively lower at GLY concentrations of 1.5% or greater (P > 0.05). No holes caused by sperms were seen in unfertilized eggs. The corresponding fertility results showed similar reductions when the GLY concentration was 1.5% or greater. No changes in the number of SP-holes were seen with increasing EY concentrations (0%–7.5%), nor were any differences in fertility observed, except for a reduction when 15% EY was used. The results therefore reveal that GLY affects the transit of sperms through the oviduct in their attempt to reach the infundibulum area, limiting their access to the ovum perivitelline layer. Egg yolk had no such effect, nor did it influence acrosome reaction capacity; its mechanism of contraceptive action therefore remains unknown. The maximum GLY and EY concentrations tolerated by the rooster sperm were 0.75% and 7.5%, respectively.     

Effects of sperm preparation and bull fertility on in vitro penetration of zona-free bovine oocytes

The objectives of this study were to develop and validate a zona-free bovine oocyte penetration assay for detecting relative differences in bovine sperm fertility and to determine the effect of different sperm preparation methods on oocyte penetration. Oocytes were incubated with heparin-capacitated spermatozoa which either were or were not induced to acrosome-react with lysophosphatidylcholine. Heparin-capacitated spermatozoa treated with lysophosphatidyl-choline penetrated more oocytes and had more penetrations per oocyte than spermatozoa capacitated in heparin but not induced to acrosome-react with lysophosphatidylcholine. Spermatozoa stained with Hoechst 33342, fluorescein isothiocyanate or tetramethyl rhodamine isothiocyanate, alone or in combination, penetrated similar numbers and percentages of zona-free bovine oocytes as the similar to non-stained spermatozoa. When spermatozoa from the same ejaculate were stained with either fluorescein isothiocyanate or tetramethyl rhodamine isothiocyanate and competed in penetrating the same oocytes, the number of penetrations generated by the 2 differently stained spermatozoa was similar. Spermatozoa from bulls of differing in vivo fertilities were labeled with different fluorescent dyes, and their relative abilities to penetrate the same oocytes were assessed. Comparisons between spermatozoa from high and low fertility bulls demonstrated that high fertility spermatozoa had a significant oocyte penetrating advantage over low fertility spermatozoa in 13 of 16 paired competitions. We concluded that the results of the competitive penetration of zona-free bovine oocytes by fluorochrome-labeled spermatozoa from bulls of different fertilities were indicative of their relative in vivo fertility.     

The relationship of infertility to antibody production in the uterovaginal sperm storage tubules of turkey breeder hens

Oviductal tissue from fertile and infertile turkey breeder hens was stained immuno-histochemically to test for the presence of antibody positive cells. Relatively infertile turkey hens (< 50% fertility) were found to have antibody positive cells within the uterovaginal sperm storage tubule epithelium, while fertile turkey hens (> 90% fertility) had no antibody positive cells. Data suggest a local immune response to spermatozoa exists in the uterovaginal sperm storage tubules of the turkey hen which may have a detrimental effect on fertility.