Isolation of preantral follicles from buffalo ovaries

Abstract

Congestive heart failure due to mitral regurgitation in an Indian hill mynah bird.ONLY a small number of oocytes within an ovary are present in antral follicles. Many more oocytes, however, are present in preantral follicles, most of which are left unutilised over the reproductive life of an animal. Harvesting oocytes only from antral follicles therefore limits the number of offspring per animal and thus the optimal exploitation of female genetic material (van den Hurk and others 1997). Hence, recent efforts have been made to develop the techniques of isolation of preantral follicles in animals. The ability to harvest oocytes from preantral follicles will facilitate basic research into the control of early development, provide a source of high quality oocytes for nuclear transfer and transgenic technologies and, in the case of buffalo, develop the potential of commercial embryo transfer.The reproductive capacity of buffalo is relatively poor in comparison with cattle. Buffalo have fewer primordial follicles (Danell 1987) and a higher rate of follicular atresia (Bharadwaz and Roy 1999). The buffalo ovary contains thousands of oocytes enclosed primarily in preantral follicles but only a few mature and reach the ovulatory stage. To tap the unutilised preantral follicles for oocyte production, techniques need to be developed for the isolation of preantral folMechanical Enzymatic Hyaluronidase Trypsin Fresh ovaries Stored ovaries Fresh ovaries Stored ovaries Fresh ovaries Number of ovaries 70 55 10 6 4 Mean (se) number of PF recovered per ovary 3*90 (0-40)a 2-58 (0-46)a 20-25 (4-42)b 16-53 (5-06)b 21-50 (O)b Values in a row with different superscripts differ significantly (P<0-001) FIG 1: Preantral follicles isolated from buffalo ovaries (x 200) licles from buffalo ovaries as they have been for domestic animals such as cattle (Hulshof and others 1995, Wandji and others 1996), sheep (Cecconi and others 1999), goats (Chelikani and others 1998) and pigs (Morbeck and others 1993).However, such studies on buffalo are lacking. In this study, preantral follicles were isolated from abattoir derived buffalo ovaries using both mechanical and enzymatic methods. The efficiency of both methods was compared. A total of 145 buffalo ovaries were collected from the local abattoir on 27 different days between May and December 1998. The ovaries were collected in normal saline containing gentamicin (50 .g/ml) and were brought to the laboratory within one hour of slaughter. Extraovarian tissue was removed and the ovaries were washed thoroughly with Dulbecco's phosphate buffered saline. Some ovaries (84) were used immediately for isolation of preantral follicles and the rest were frozen overnight at 0°C for isolation on the following day. Preantral follicles were isolated by two methods, a mechanical method and an enzymatic method.In the mechanical method, the ovary was first halved with a surgical blade and the medulla was scraped off. The cortex was then sliced into pieces of approximately 1 cm3. These pieces of ovary were washed with a ...

Viability and Growth of Buffalo Preantral Follicles and their Corresponding Oocytes In Vitro: Effect of Growth Factors and β Mercaptoethanol

“…As the ovarian tissue in buffaloes is more fibrous, mechanical method could yield very less number of large PFs (Gupta et al. 2001).…”

“…To tap the unutilized PFs for oocyte production, procedures need to be standardized for the isolation of PFs from buffalo ovaries. Procedures of preantral follicular isolation are standardized for buffalo (Gupta et al. 2001, 2002, 2007a).…”

Isolation and Culture of Ovine and Bubaline Small and Large Pre‐antral Follicles: Effect of Cyclicity and Presence of a Dominant Follicle

“…2002) compared with 12 000–19 000 in buffalo (Samad and Nasseri 1979). It is also likely that the lower yield might be due to more fibrous nature of buffalo ovaries (Gupta et al. 2001).…”

Characterization of folliculogenesis and the occurrence of apoptosis in the development of the bovine fetal ovary

“…Several techniques have been developed to isolate oocytes and/or follicles, including mechanical isolation and in vitro culture of preantral follicles [24][25][26][27][28][29][30][31][32][33][34]. In this study, we used mechanical isolation of follicles, with the objective of characterizing follicular density, in situ morphometry, and the occurrence of apoptosis in ovaries obtained from bovine fetuses of various ages.…”