Publication Date: 2015.
The objectives of this study were to compare the effects of two intravaginal devices (ID) containing the same dose (0.5 g) of progesterone (P4) on subsequent ovarian response, embryo production and circulating P4 concentration profile in llamas (Lama glama) treated with equine chorionic gonadotropin (eCG) for ovarian superstimulation. Female llamas were randomly assigned (n = 10 llamas per group) to one of the following groups and treated (Day 0) with an ID containing 0.5 g of vegetal P4 to synchronize the emergence of a new follicular wave: i) DIB 0.5® and ii) Cronipres M15®. On Day 3 llamas were intramuscularly treated with 1000 IU of eCG. The IDs were removed on Day 7. Llamas were naturally mated (Day 9) and treated with GnRH analogue to induce ovulation. A second mating was allowed 24 h later. Embryos were collected between 7 and 8 days after the first mating. Blood samples were taken every day from Day 0 to Day 7 to measure circulating P4 concentrations. The results indicated that DIB device maintained greater plasma P4 levels as compared to Cronipres until Day 2. However, the mean (± SD) number of corpora lutea and recovered embryos was not affected (p < 0.05) by the type of ID (5.3 ± 2.6 vs 4.2 ± 2.2 and 3.5 ± 2.7 vs 2.6 ± 3.0 for DIB and Cronipres, respectively). In conclusion, both DIB and Cronipres devices can be successfully used to synchronize the emergence of follicular wave prior to a single dose of eCG in superovulation protocol in llamas.
Author affiliation: Aller Atucha, Juan Florencio. INTA. Estación Experimental Agropecuaria Balcarce; Argentina
Author affiliation: Abalos, Marcos. INTA, Estación Experimental Agropecuaria Abra Pampa; Argentina
Author affiliation: Acuña, Francisco Antonio. INTA, Estación Experimental Agropecuaria Abra Pampa; Argentina
Author affiliation: Virgili, Rosana. Universidad Nacional de Jujuy. Facultad de Ciencias Agrarias; Argentina
Author affiliation: Requena, Francisco. Universidad de Córdoba. Facultad de Veterinaria. Campus Universitario Rabanales; España
Author affiliation: Cancino, Andrea Karina. INTA. Estación Experimental Agropecuaria Bariloche; Argentina
Keywords: Embriones Animales; Animal Embryos; Superovulation; Hormonal Regulation; Superovulación; Progesterona; Llama; Lama Glama; PMSG; Regulación Hormonal; Gonadotropina Coriónica Equina; Dispositivos Intravaginales; Tratamiento Hormonal; eCG; Intravaginal Devices; Equine Chorionic Gonadotropin; Hormonal Treatment.
Repository: INTA Digital (INTA). Instituto Nacional de Tecnología Agropecuaria
Publication Date: 2011.
Cholesterol transport is essential for many physiological processes, including steroidogenesis. In steroidogenic cells hormone-induced cholesterol transport is controlled by a protein complex that includes steroidogenic acute regulatory protein (StAR). Star is expressed as 3.5-, 2.8-, and 1.6-kb transcripts that differ only in their 3′-untranslated regions. Because these transcripts share the same promoter, mRNA stability may be involved in their differential regulation and expression. Recently, the identification of natural antisense transcripts (NATs) has added another level of regulation to eukaryotic gene expression. Here we identified a new NAT that is complementary to the spliced Star mRNA sequence. Using 5′ and 3′ RACE, strand-specific RT-PCR, and ribonuclease protection assays, we demonstrated that Star NAT is expressed in MA-10 Leydig cells and steroidogenic murine tissues. Furthermore, we established that human chorionic gonadotropin stimulates Star NAT expression via cAMP. Our results show that sense-antisense Star RNAs may be coordinately regulated since they are co-expressed in MA-10 cells. Overexpression of Star NAT had a differential effect on the expression of the different Star sense transcripts following cAMP stimulation. Meanwhile, the levels of StAR protein and progesterone production were downregulated in the presence of Star NAT. Our data identify antisense transcription as an additional mechanism involved in the regulation of steroid biosynthesis.
Author affiliation: Castillo, Ana Fernanda. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquimica Humana. Catedra de Quimica Biologica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Author affiliation: Fan, Jinjiang. Mc Gill University; Canadá
Author affiliation: Papadopoulos, Vassilios. Mc Gill University; Canadá
Author affiliation: Podesta, Ernesto Jorge. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Repository: CONICET Digital (CONICET). Consejo Nacional de Investigaciones Científicas y Técnicas