Expression of a bovine growth hormone transgene inhibits pregnant mare's serum gonadotropin-induced follicle maturation in prepuberal gilts
| Autor: | D. J. Bolt, B.S. Cooper, Vernon G. Pursel, H.D. Guthrie |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
medicine.medical_specialty
Gonadotropins Equine Swine medicine.drug_class Follicular Atresia Gene Expression Biology Animals Genetically Modified Follicle Ovarian Follicle In vivo Internal medicine Genetics medicine Animals Inhibins Bovine somatotropin Androstenedione Progesterone Estradiol Theca interna General Medicine Androgen Follicular fluid Follicular Fluid Endocrinology Estrogen Growth Hormone Female Animal Science and Zoology Food Science |
| Zdroj: | Journal of Animal Science. 71:3409-3413 |
| ISSN: | 1525-3163 0021-8812 |
| DOI: | 10.2527/1993.71123409x |
| Popis: | Prepuberal gilts were injected with PMSG to determine whether expression of a bovine growth hormone (bGH) transgene inhibited preovula- tory maturation of ovarian follicles. Seven transgenic (TG) gilts of line 3706, which expresses a mouse metallothionein-bGH transgene, and eight nontrans- genic, control (C) gilts (128 to 147 d old) were injected with PMSG, 12.5 IU/kg BW, 72 h before necropsy. Surface ovarian follicles 2 1 mm in diameter were counted, measured for diameter, and aspirated for fluid. Follicles were classified morphologxally as healthy or atretic and those with follicular fluid estradiol-170 2 100 ng/mL were classified as estrogen- active (EA). The number of follicles per gilt was 64.3 f 6.1 (mean f SEM) and did not differ significantly between bGH-TG and C gilts. The PMSG treatment induced growth of large (> 5 mm) follicles in both bGH-TG and C gilts. However, compared with C gilts, bGH-TG gilts had fewer (P < .05) large follicles (5.9 f 1.5 vs 18.3 k 5.4), a lower proportion of EA large follicles (35 ?c 12.5 vs 69 k 13.2%), and in large follicles less (P < .05) estradiol-170 (86 k 17 vs 350 f 69 ng/mL) and androstenedione (300 k 33 vs 1,283 f 221 ng/mL). Follicular fluid progesterone and inhibin did not differ significantly between bGH-TG and C gilts. The incidence of atresia among small and medium follicles did not differ significantly between bGH-TG and C gilts. These results indicate that chronic, unregulated expression of a bGH transgene in prepuberal gilts inhibited follicle growth in response to administration of PMSG and may have blocked estradiol-17P production in vivo by inhibiting theca interna androgen production. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|