Category Archives: Oocytes

Parthenogenetic Activation of Marmoset: DISCUSSION(5)

De Groot et al. showed that the abundance of total p-subunit of CG in maternal serum is proportional to the number of paternal genomes carried by hy-datidiform moles (2 paternal), partial moles (2 paternal, 1 maternal), triploid conceptuses (2 maternal, 1 paternal), and normal conceptuses (1 paternal, 1 maternal). Additionally, the levels of p-hCG in the serum of human triploid con-ceptuses with one paternal and two maternal genomes are abnormally low compared to those that carry two paternal genomes. Since parthenogenetic embryos do not carry paternal genomes, an imprinted gene for p-CG could explain the apparent absence of CG in the maternal plasma. Cheap Diskus Advair

Parthenogenetic Activation of Marmoset: DISCUSSION(4)

DISCUSSION(4)

These workers propose that the CL may be able to respond to extremely small amounts of CG but do not rule out the possibility that some other luteotropic or anti-luteolytic factor maintains the CL while CG rises to concentrations able to provide luteotropic support. Evidence from inhibin studies in marmosets supports the latter possibility, as there is a significant rise in inhibin production by Day 8 after ovulation in conception cycles compared to nonconception cycles. At this early stage of development, the production of CG by marmoset embryos is undetectable both in vitro and in vivo. It is possible that the embryo produces another factor for maternal recognition at preimplantation stages that causes this significant rise in inhibin production from the CL. Buy Advair Diskus Online

Parthenogenetic Activation of Marmoset: DISCUSSION(3)

In primates, the most important signal yet described for the maternal recognition of pregnancy is CG. Marmosets passively or actively immunized against human CG p-subunit during the first 6 wk of gestation lose their pregnancies. Therefore, hormone profiles shown here for recipients of parthenogenetic embryos were interesting because both progesterone and ir-inhibin, produced by the CL in marmosets, were maintained at levels that would be associated with continued luteotropic support. ampicillin antibiotic

Parthenogenetic Activation of Marmoset: DISCUSSION(2)

DISCUSSION(2)

This may have been due to the age of the oocytes at treatment since aging affects the type of murine development after parthenogenetic activation, and meiotic spindles migrate to the center of mouse oocytes during the aging process. Increased immediate cleavage of mouse oocytes was observed after 36 h of in vitro culture, and this effect may also have occurred in marmoset oocytes but over a longer time span (3 days in vitro culture). The culture time required to observe this effect may be related to the length of the cell cycle in preimplantation stages: marmoset embryos take four days to reach the 8-cell stage, the same length of time taken for mouse embryos to reach the blastocyst stage. antibiotics levaquin

Parthenogenetic Activation of Marmoset: DISCUSSION(1)

This study has shown that marmoset oocytes can be par-thenogenetically activated by electrical stimulation or ethanol treatment. Ninety-two percent of marmoset oocytes were activated by multiple electrical pulses. This is comparable to the rate of human oocyte activation (95%) using mannitol exposure and electrical stimulation. Human oocytes can be activated by ethanol at rates of 16%, similar to the 20% activation rate described here for marmoset oocytes using the same method.

Parthenogenetic Activation of Marmoset: RESULTS(5)

RESULTS(5)

The invasion of the syncy-tiotrophoblast into the stromal tissue of the endometrium could be seen as “finger-like” projections of tissue displaying multinucleated cells typical of syncytium. This cell layer surrounded the blood vessels underlying the apical endometrial epithelium, which had undergone a typical hypertrophy and proliferative response (Fig. 2B). By comparison, the apical endometrium of a nonpregnant marmoset showed no hypertrophy of blood vessels, and the endometrium was of regular appearance (Fig. 2A). The decidual reaction in the marmoset monkey is minor compared to that of other primates, so the lack of a decidual reaction in Figure 2B did not necessarily indicate that the animal was not pregnant. buy cheap antibiotics

Parthenogenetic Activation of Marmoset: RESULTS(4)

Ir-Inhibin Profiles of Recipient Marmosets

Previous studies have shown a significant difference in ir-inhibin levels between conception and nonconception cycles before implantation. During the first 26 days of gestation, animals 345W and 457W (IVF embryo recipients) had total ir-inhibin levels of 2.2 and 1.7 ug X days/ ml, respectively. The nonpregnant animal (323W) had a total ir-inhibin over the same 26 days of 1.4 ug X days/ ml. However, total ir-inhibin levels of 469W and 491W (parthenogenetic embryo recipients) during the first 26 days of gestation were 2.7 and 2.9 ug X days/ml, respectively. That is, the peripheral plasma ir-inhibin levels of the par-thenogenetic embryo recipients were 1.5 times higher than those of the IVF embryo recipients and 2 times higher than those of the nonpregnant animal. birth control yasmin

Parthenogenetic Activation of Marmoset: RESULTS(3)

RESULTS(3)

The levels of progesterone in the peripheral plasma of both animals (345W and 457W) that received biparental IVF embryos rose steadily to about 100-120 ng/ml and remained high, typical of progesterone profiles of pregnancy (Fig. 1A). Of the three animals that received partheno-genetic embryos, two animals (469W and 491W) had progesterone profiles resembling those of pregnant marmosets (Fig. 1C), and one recipient (323W) had a progesterone profile typical of a nonpregnant animal (Fig. 1E). Continued high progesterone levels in animals 469W and 491W for 33 days after ovulation would suggest that the CL was maintained, and this was confirmed visually when these recipient marmosets were killed.

Parthenogenetic Activation of Marmoset: RESULTS(2)

Activation and Development of Marmoset Oocytes Exposed to Ethanol

Twenty percent (8 of 40) of oocytes exposed to ethanol were activated. Three types of development after activation were observed. Five (63%) activated oocytes underwent IC and had divided to 2 cells within 6-18 h of treatment; two oocytes (25%) were 2PB,1PN; and one oocyte was 1PB,2PN. Only the oocytes that underwent IC divided in culture. One of these embryos developed to 16 cells, one to 6 cells, one to 3 cells, and two to 2 cells in vitro. Overall, the average cell number (± SEM) of ethanol-activated par-thenogenones was 4.0 ± 1.7. This was not significantly different from the average cell number reached by electrically stimulated parthenogenetic embryos. buy yasmin online
None of the control oocytes (0 of 19) were partheno-genetically activated.

Parthenogenetic Activation of Marmoset: RESULTS(1)

RESULTS(1)

Oocyte Collection

A total of 122 oocytes were collected for this study, from 51 laparotomies. The average number of follicles per animal was 2.6, and the mean number of oocytes collected per animal was 2.4. buy ventolin inhalers

Visualization of Activation Events

Six hours after activation stimulus, some oocytes had undergone immediate cleavage (IC) to 2 cells. After 18-20 h, oocytes had either cleaved (IC), extruded a second polar body and formed one pronucleus (2PB,1PN), formed one pronucleus without extruding a second polar body (1PB,1PN), formed two pronuclei without extruding a second polar body (1PB,2PN), or failed to activate. These events occurred with the same timing after activation stimulus, regardless of whether ethanol or electrical stimulation was used.

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