Follicular expression of a human beta-cell leukaemia/lymphoma-2 (Bcl-2) transgene does not decrease atresia or increase ovulation rate in swine.
Transgenic (TG) gilts carrying a human Bcl-2 cDNA transgene driven by mouse inhibin-alpha subunit promoter were produced and evaluated to determine if ectopic expression of Bcl-2 in the ovaries would decrease the frequency of atresia in antral follicles and increase ovulation rate. Immunohistochemical analysis showed that the Bcl-2 transgene protein was expressed in granulosa and theca cells, in 86% of healthy and 54% of atretic follicles analysed in TG prepubertal and Day 50 pregnant gilts combined (n = 24). In contrast, Bcl-2 transgene protein was expressed in only 1.4% of healthy and 0% of atretic follicles in non-TG littermates (n = 13). Real-time reverse transcription-polymerase chain reaction analysis confirmed that human Bcl-2 was expressed in follicles of TG gilts. The atresia rate for the TG and non-TG groups did not differ (P > 0.05) for prepubertal (45 v. 59%) and Day 50 pregnant gilts (53 v. 52%) respectively. The mean +/- s.e.m. ovulation rate did not differ (P > 0.5) between TG (15.9 +/- 0.8, n = 12) and non-TG (16.4 +/- 0.6, n = 7) Day 50 pregnant gilts. The molecular basis of the failure of ectopic Bcl-2 expression to increase the ratio of healthy to atretic follicles is unknown, but it is possible that the activity of the mitochondrial-dependent cell death pathway was not neutralized by ectopic expression of human Bcl-2 or that other cell death pathways compensated for the decreased mitochondrial-dependent cell death.
Guthrie
H D
HD
Biotechnology and Germplasm Laboratory, Animal and Natural Resources Institute, Agricultural Research Service, USDA, Beltsville, MD 20705, USA.
Wall
R J
RJ
Pursel
V G
VG
Foster-Frey
J A
JA
Donovan
D M
DM
Dawson
H D
HD
Welch
G R
GR
Garrett
W G
WG
D000818:Animals; D030801:Animals, Genetically Modified; D005260:Female; D005496:Follicular Atresia / Q000235:genetics*; D015870:Gene Expression; D006801:Humans; D008297:Male; D006080:Ovarian Follicle / Q000502:physiology*; D010053:Ovary / Q000502:physiology; D010060:Ovulation / Q000235:genetics*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism*; D013552:Swine; D013737:Testis / Q000502:physiology
D019253:Proto-Oncogene Proteins c-bcl-2