Introduction Of Sperm Research Articles

Cytological characteristics of vaginal smears in ewes during the sexual cycle and during pregnancy

New criteria for cytological analysis of sheep vaginal swabs (cytovaginal examination) during sexual hunting, during the sexual cycle, after insemination and depending on the effectiveness of insemination have been developed. Cytological material was collected from the area of the upper vaginal vault using a sterile vaginal mirror, forceps and cotton gauze swab. Staining of brushstrokes was performed according to Gimza-Romanovsky. To improve the method of cytovaginal examination, the division of smear epitheliocytes into groups: functional, destroyed, non-nuclear and cells with nuclear pyknosis is proposed. In turn, among the functional cells it is advisable to distinguish between cells of the deep layers of the epithelium (basal-parabasal), intermediate and surface layer (superficial nuclear). The main types of ratio of particles of different groups and subgroups and their prognostic value in the mating season during sexual hunting are revealed. It was found that during the inhibition stage there is an intensive desquamation of the epithelial level, which was manifested by a 2.5-fold decrease in the number of basal / parabasal epitheliocytes and almost four - destroyed epitheliocytes. And already from the 13th day there is an increase in the cells of the functional level due to the proportion of cells of the deep and intermediate level. On the 18th day, the cellular composition of vaginal smears in sheep acquired characteristics characteristic of the stage of arousal. Thus, compared with the 6-8th day of the cycle, the number of destroyed epitheliocytes (p <0.001) and naked nuclei (up to 8.3 ± 1.6) doubled again (up to 12.0 ± 0.7) against the background of a decrease in 4 times (to the initial level) of cells with pyknosis of the nucleus. The main cytological sign of pregnancy from the fourth day after insemination was a 2.7-fold increase in the number of destroyed cells and "naked" nuclei. In the following days of the study, except for the 13th day, this difference ranged from 1.3 to 4.3 times (8.3 ± 5.4 to 14.7 ± 3.6%), compared with the corresponding figures in unfertilized ewes. Also on the 13th day after the introduction of sperm in fertilized females there is a tendency to increase the number of deep layer cells and the acquisition on the 18th day of a probable difference in the ratio between the number of deep and surface cells - 5: 1. Changes in the distribution of deep and surface cell particles in unfertilized animals indicate the manifestation of the next stage of excitation and the predominance of epithelial cell differentiation. In contrast, in pregnant females, the proliferation of the deep layers of the vaginal epithelium increased. Key words: ewes, sexual cycle, sexual hunting, vaginal smear, cytological composition, pregnancy.

Obtaining Xenopus tropicalis Embryos by In Vitro Fertilization.

Xenopus is a powerful model system for cell and developmental biology in part because frogs produce thousands of eggs and embryos year-round. In vitro fertilization (IVF) is ideal for obtaining developmentally synchronized embryos for microinjection or when natural mating has failed to produce a fertilization. In IVF, females are induced to ovulate, and then eggs are collected by manual expression. After testes are collected from a euthanized male frog, the eggs are fertilized in vitro. The embryos are then treated with cysteine to remove the sticky protective jelly coat. Dejellied embryos are much easier to manipulate during microinjection or when sorting in a Petri dish. The jelly coat is also very difficult to penetrate with an injection needle. After microinjection, embryos are maintained in Petri dishes until desired stages are reached. Although in vitro fertilization in X. laevis and X. tropicalis is similar, critical differences in solutions, handling of testis, response of fertilized eggs directly after introduction of sperm, and developmental timing are required for successful fertilization in X. tropicalis.

Optimal timing of artificial insemination in gilts

In the article it is highlighted the results of research on the features of cervix permeability and optimal periods of fertilization in pubertal gilts. Five high-productive boars of the Large White breed, aged 18-36 months, were used in experiments and evaluated for the quality of sperm. The start of the estrus was carried out using a test boar. In the first experiment to determine the permeability of the cervical canal, 3 groups of the Large White breed were formed for 15 heads in each, which were inseminated at the onset: of the first (1st group), the second (2nd group) and the third period of the estrus at the age of 6 - 8 months. Gilt were fertilized with a sperm dosage of 70 ml of a diluent containing 2 billion of spermatozoa. In the second experiment to determine the optimal timing of insemination, 66 gilt of the Large White breed aged 8 to 9 months, live weight 110-130 kg, with clear signs of the start of proestrus, estrus and diestrus were used. The beginning of the estrus was set twice a day at 7 o'clock and 19 o'clock. The doses of sperm (2 billion of spermatozoa in 70 ml of diluent) were injected into the gilts according to the following scheme: Group I - after the prescribed period of the estrus - 0 hours; Group II - after 6 hours; III - group - 12 hours; Group IV - 18 hours; V - 24 hours; VI - 36 hours. It has been determined that cervical permeability increases with age of gilts and the number of reproductive cycles. In gilts, in the first reproductive cycle, the permeability of the cervical canal is 4.61 cm and intensively increases twice: 1.9 (p <0.001) (2nd estrus) and 2.5 times (p <0.001) (3rd estrus). The introduction of sperm by the intracerviсal method on the third period of the estrus allows them to be fertilized at a level of 86 % and receive 10.2 newborn piglets.Cervix permeability in gilts increases from the beginning of the estrus for the next 24 hours. The high indexes of their reproductive capacity are determined at the introduction of sperm dosage in 24-36 hours after the onset of the estrus. The number of live newborns piglets was maximal when sperm is introduced into cervix of gilts in 12; 24 and 30 hours after the start of the estrus. The live weight of newborn piglets depends on the period of the introduction of sperm into the pigs, being maximal at the start of the estrus, and in 24 and 30 hours after the introduction of sperm. The postponement of the procedure up to 36 hours leads to a decrease of this index (p <0.001). Key words: reproductive cycle, estrus, cervix, fertilization, sperm, gilt.

ANATOMICAL STRUCTURE OF INTERNAL GENITAL ORGANS ZAANEN BREE

Goal. Goat breeding is a promising branch of animal husbandry, which is rapidly developing. The scientific literature has little information about the essential features and differences in the structure of the genital apparatus of goats. With the increase in the number of livestock and selection work in goat breeding, knowledge of the characteristics of the reproductive system is of great importance. Due to lack of knowledge of the structure of the reproductive organs of small cattle, the effectiveness of artificial insemination decreases and inefficient sperm of producers is used, since the complex structure of the cervix of the goat is an obstacle in the artificial introduction of sperm. Therefore, considering the need for further introduction of the method of artificial insemination into practice of goat breeding, the study of the peculiarities of the structure of the internal genital organs of goats is timely and necessary.
 Materials and methods.The study of anatomical features of the structure of the internal genital organs of goats was carried out on animals of the Zaanen breed, imported into the village. Galaiki Tarashchansky district of the Kiev region from Latvia. The material for study was the genitals obtained from goats aged 6-7 years. After the slaughter and bleeding, the genitals were separated into goats. They were then placed in an enameled cuvette and measured with a measuring tape, ruler and caliper. The linear dimensions of the ovaries, the diameter and length of the uterine horns according to the large curvature, the length of the uterine body, the length and diameter of the cervix, the number and structural features of the folds of its mucous membrane, the amount of caruncle, their height and diameter were measured.
 As mentioned earlier, the development of anatomical and physiological basis for artificial insemination of small ruminant animals was carried out mainly on sheep. Therefore, we compared the size of the ovaries, oviducts and uterus in goats of the Zaanen breed of Latvian selection and, according to the literature, the results of studies of similar sheep organs were analyzed.
 As a result of the studies of the morphological parameters of the genitalia of the goats, the following data were obtained: the mass of the left ovary – 0,6 ± 0,06 g, the right – 1,1 ± 0,04 g: the length of the left ovary – 2,0 ± 0,06 Cm, the length of the right – 2,3 ± 0,04 cm. The length of the left oviduct was – 14,2 ± 0,16 cm, and the right – 14,4 ± 0,15 cm. Accordingly, the length of the left horn of the uterus was – 13,7 ± 0,63 cm, the right – 12.2 ± 0,75 cm. The diameter of the left horn of the uterus is – 2.3 ± 0,07 cm, the right horn of the uterus is – 2,8 ± 0,08 cm.
 The morphological parameters of the unpaired genitals of goats were as follows:
 The length of the uterus body was – 1,8 ± 0,15 cm, the cervix was – 5,9 ± 0,29 cm, the cervix diameter was – 1,8 ± 0,08 cm; the number of folds in the cervix is – 4,7 ± 0,50. The height of the caruncle is – 0,5 ± 0,06 cm, their diameter is – 0,7 ± 0,10 cm, the amount of caruncle is – 96,5 ± 1,70, the area of the caruncle is on average – 0,4 ± 0,10 cm2.
 Conclusions. As a result of the carried out researches the anatomical and morphometric characteristics of internal sexual organs of goats are given. These data make it possible to expand and supplement knowledge on the morphology of the reproductive system of farm animals, which must be taken into account in artificial insemination of goats. The data obtained by us are somewhat different from the results of the studies of other authors, but do not contradict them.

On the control of oocyte meiotic maturation and ovulation in Caenorhabditis elegans.

Prior to fertilization, oocytes undergo meiotic maturation (cell cycle progression) and ovulation (expulsion from the ovary). To begin the study of these processes in Caenorhabditis elegans, we have defined a time line of germline and somatic events by video microscopy. As the oocyte matures, its nuclear envelope breaks down and its cell cortex rearranges. Immediately thereafter, the oocyte is ovulated by increasing contraction of the myoepithelial gonadal sheath and relaxation of the distal spermatheca. By systematically altering the germ cell contents of the hermaphrodite using mutant strains, we have uncovered evidence of four cell-cell interactions that regulate maturation and ovulation. (1) Both spermatids and spermatozoa induce oocyte maturation. In animals with a feminized germline, maturation is inhibited and oocytes arrest in diakinesis. The introduction of sperm by mating restores maturation. (2) Sperm also directly promote sheath contraction. In animals with a feminized or tumorous germline, contractions are infrequent, whereas in animals with a masculinized germline or with sperm introduced by mating, contractions are frequent. (3 and 4) The maturing oocyte both induces spermathecal dilation and modulates sheath contractions at ovulation; dilation of the distal spermatheca and sharp increases in sheath contraction rates are only observed in the presence of a maturing oocyte.

Is sperm immunosuppressive in male homosexuals and vasectomized men?

Recently a high incidence of uncommon diseases including Pneumocystis carinii pneumonia and Kaposis sarcoma have been observed among male homosexuals. Various cellular immune functions are impaired in these patients; the mechanism of the immunodeficiency is not known although it is believed that multiple viral infections and/or certain drugs such as nitrites which these patients use may be important. The authors suggest that one of the causes of immunosuppression could be the introduction of sperm into the vascular system. The repeated exposure of the immune system to germ-cell antigens and the synergistic effect of viruses and/or drugs may exert this effect. In laboratory experiments a number of cellular immune functions of sperm-injected mice were reduced including cytotoxic T-cell responses against hapten-modified self and alloantigens as well as mixed lymphocyte reactivity. Natural killer-cell function was also impaired. Sperm could gain access to the vascular system through: 1) intestinal or oral lesions which are found in most affected individuals and 2) increased permeability of the blood vesicles of the intestinal and/or oral mucosa. These conditions are also related to nitrite use; thus it is possible that this type of immunodeficiency is multi-factorial. The increased incidence of neoplasms among male homosexuals could provide an opportunity to investigate the relationship between immunodeficiency and tumor surveillance. In vasectomized males immune potential may be compromised by leakage of sperm into the vascular system; major histocompatiblity complex (MHC)-linked regulation of antisperm auto-antibody production after vasectomy has been reported in mice and men. Animal models will allow further investigation of this phenomenon including the synergistic effects of sperm virus and drugs and clinical studies could consider the role of MHC-linked genes the influence of age viral infection and drug usage.

Notes on Haliotis tuberculata. I

1. Eggs may be clearly differentiated in a female specimen of Haliotis before a length of 2 cm. is reached by the animal, and the female gonad visible before 3 cm. is reached. The female may spawn at 5·5 cm. In the male, active sperms with tails may be differentiated before a length of 3 cm. is attained, and the gonad visible before 4 cm. is reached. The male may spawn at 5·5 cm., if not before.2. It is estimated that specimens up to about 3·5 cm. long are a year old or less. If so, male and female can both spawn at three years old at any rate, more likely at two years.3. The first week in August certainly lies within the breeding season. The range of that season is not known, but evidence points to its being late summer.4. The male gonad is typically white or cream-coloured, or with a tinge of green in addition; rarely salmon or pale yellow. The female gonad varies more, various shades of green, grey-green, brownish grey, etc., are found. These data refer to specimens observed in June and July.5. Of 127 specimens examined for sex, 50 were males, 71 females, 6 young ones not giving decisive evidence.6. A male and female were seen spawning. The male puffed out successive clouds of sperms. The female puffed out one cloud of eggs through the holes in the shell, perhaps 10,000 of them. They sank rapidly. They were visible to the naked eye, pale green and quite free from one another. Each was enclosed in a transparent shell.7. Fertilisation took place after the eggs were laid. The young had reached an early trochophore stage at fourteen to fifteen hours after introduction of sperm. At forty-four to forty-six hours many had left the egg shell and were swimming actively, being then at a decidedly more advanced trochophore stage. How long it is before they settle down and end the larval stage is not known.8. The food supply consists of algae (both coarse ones and confervas, also diatoms), polyzoa, sponges, small Crustacea, foraminifera, etc. A good deal of sand is taken in with it.9. Haliotis is certainly a browser and uses the radula as a licking tongue. Experiments were. made to ascertain whether it can extract plankton from the water as part of its food as Crepidula does. The results were interesting (see p. 487), but not conclusive, pointing to inability to use plankton.10. There is no evidence to show that Haliotis is a homing mollusc like Patella, what there is pointing the other way. It is an exceedingly active species.11. Haliotis demands the highest possible conditions of aeration in its water. Given these it is hardy, and will even live for months after removal of its shell, secreting one or more new ones (Boutan).12. In the attempt to find out why Haliotis is getting scarcer in Guernsey and the neighbouring islands (leaving Jersey out of account), it was concluded that this could probably be brought about by overfishing, and by a too ruthless disturbance of the beaches, leading to a certain diminution of the food supply over the area within which Haliotis is available for fishing. If this is not the main cause, some kind of natural fluctuation may account for i t; contamination, natural enemies, etc., not appearing to be main factors. The fishing of Haliotis in Guernsey has consequently been totally suspended by the States for a period of two years. At the end of that time more permanent regulations will be devised.