A homology guide for Pacific salmon genus resolves patterns of ohnolog retention, resolution and local adaptation following the salmonid-specific whole-genome duplication event.

Salmonid fishes have emerged as a tractable model to study whole-genome duplications (WGDs) as this group has undergone four rounds of WGDs. While most of the salmonid genome has returned to a diploid state, a significant proportion of genes are maintained as duplicates and are referred to as ohnologs. The fact that much of the modern salmonid gene repertoire is comprised of ohnologs, while other genes have returned to their singleton state creates complications for genetic studies by obscuring homology relationships.

Calf presence and estrous response, ovarian follicular activity and the pattern of luteinizing hormone in postpartum cows.

The main objective of the present experiment was to assess the effect of temporary weaning on the onset of estrus, ovarian follicular activity and secretion of luteinizing hormone in cows. Forty six mature cows were divided into three groups 1) calves were weaned for 72 h allowing auditory, olfactory and visual contact with their dams (VISUAL, n = 17), 2) calves without contact with their dams for 72 h (NC, n = 17) and 3) calves not weaned and in constant contact with their dams (CTRL, n = 12). Estrus was synchronized in all cows using CIDR for 9 days plus 2 mg of estradiol benzoate given at CIDR insertion.

Short communication: Temporal effect of feeding potassium carbonate sesquihydrate on milk fat in lactating dairy cows fed a fat-depressing diet.

A lactation study with 10 multiparous dairy cows in early lactation, with an average of 64 days in milk (standard deviation=37), were used to evaluate how quickly milk fat concentration would change when potassium carbonate sesquihydrate was abruptly added to the diet. The experiment had 3 periods. In period 1 (d 0 to 7) all cows were fed the same basal (control) diet with 1.

The role of phosphoinositide-derived second messengers in oxytocin-stimulated prostaglandin F2 alpha release from endometrium of pigs.

The mechanism for prostaglandin (PG) F2 alpha release from pig endometrium after oxytocin (OT) treatment is unknown. OT may rapidly stimulate inositol (1,4,5)-trisphosphate (IP3) and diacylglycerol (DAG) formation, consistent with the concept of rapid activation of a second-messenger system. In support of this hypothesis, endometrial IP3 levels were increased (P < 0.

Development of in vitro matured and fertilized bovine oocytes co-cultured with Buffalo Rat Liver cells.

This study was designed to evaluate the efficacy of Buffalo Rat Liver cells (BRLC) monolayers in supporting the development of in vitro matured and fertilized (IVM/IVF) bovine oocytes through to the hatched blastocyst stage compared to the commonly used co-culture system of bovine oviduct epithelial cells (BOEC). Cumulus oocyte complexes (COCs) obtained from 2- to 6-mm ovarian follicles at slaughter were matured for 24 h in TCM-199 supplemented with FBS and hormones (FSH, LH and estradiol 17-beta). In vitro fertilization (IVF) was performed using 1 x 10(6) percoll separated frozen-thawed spermatozoa in 1 ml of IVF-TL medium containing 18 to 20 matured oocytes.

Effect of sperm exposure time on in vitro fertilization and embryo development of bovine oocytes matured in vitro.

This study was designed to investigate the effect of sperm exposure time on the fertilization rate and subsequent developmental capacity of bovine oocytes matured in vitro. Cumulus oocyte complexes (COCs) obtained from 2 to 6 mm follicles were matured for 24 h in TCM-199 supplemented with fetal bovine serum (FBS) and hormones (FSH, LH and estradiol 17-beta). In vitro fertilization (IVF) was performed by incubating 15 to 20 matured oocytes with 1 x 10(6) percoll separated frozen-thawed spermatozoa in 1 ml of IVF-TL medium for either 4, 8, 12, 16, 20, 24 or 28 h.

Effects of blood monocytes and lymphocytes on progesterone secretion by granulosa cells in the pig.

We studied the effects of autologous and nonautologous co-cultures of porcine blood monocytes and lymphocytes with granulosa cells on progesterone secretion. Eight prepubertal crossbred gilts were ovariectomized, and the granulosa cells were collected, plated at 2.5 x 10(5) cells/ml and allowed to attach.

Deep freezing of mouse one-cell embryos and oocytes using different cryoprotectants.

The objective of this study was to compare iso-osmolar concentrations (1.5 M) of 1,2-propanediol, glycerol, dimethylsulphoxide and a combination of 1 M propanediol + 0.5M glycerol (PDGLY) as cryoprotectants for murine ovulated oocytes and one-cell embryos.

Glucose utilization by enzymatically-formed trophoblastic vesicles and Day-14 porcine blastocysts.

The total glucose metabolism of 48-h spherical trophoblastic vesicles, Day-60 trophoblastic vesicles sections and Day-14 porcine blastocyst sections was measured by the method of O'Fallon and Wright (1). Trophoblastic vesicles were formed by enzyme dispersal in Day-14 porcine blastocysts. Glucose was based on DNA content of the tissue measured by diamino benzoic acid reaction with DNA (2).

Relationships between days post partum, observed estrus and uterine microflora in commercial dairy cows.

This study was conducted to determine relationships between the uterine microflora and reproductive characteristics of dairy cows. Uterine lumina were swabbed during estrus immediately prior to artificial insemination (A I). Swabbings were cultured for bacteria and accessed for cytologic evidence of inflammation.

Effect of one-step sucrose dilution of glycerol on in-vitro development of frozen-thawed mouse embyros.

Several glycerol (GLY) dilution treatments were compared using frozen-thawed early blastocysts from Swiss Webster mice. These treatments consisted of 0.00 (0.

Synchronization of estrus in yearling beef heifers with melengestrol acetate and prostaglandin F(2alpha).

This study was designed to test the efficacy of melengestrol acetate (MGA) in combination with prostaglandin F(2alpha) (PGF(2alpha)) in synchronizing estrus in cyclic and noncyclic heifers. One hundred thirty-one cyclic and prepubertal crossbred heifers were randomly assigned to three treatment groups: Controls (n = 43); MGA (0.5 mg/d for 7 d) and PGF(2alpha) (25 mg i.

Cold culture of different stage mouse embryos in bicarbonated and bicarbonate-free media.

Mouse embryos of different stages of development were cultured to expanded blastocysts following storage (1 to 8 d) at 4 degrees C in the presence or absence of HCO(3)(-). The effect of oxygen tension on the cold storage of one- and two-cell mouse embryos at 4 degrees C was evaluated by 37 degrees C culture and transfer to pseudopregnant recipients. Survival at 4 degrees C of early, one- to four-cell mouse embryos was improved with HCO(3)(-) in the medium.

In vitro culture and maintenance of trophoblastic vesicles: Observations on the development of contractile structures with concurrent vessel development.

The use of trophoblastic vesicles as a model for the study of maternal recognition of pregnancy, embryo development and cell to cell interaction has increased in recent years. In this report, we describe the long-term culture of trophoblastic vesicles derived from enzymatically dispersed porcine blastocysts. Day 12 to 14 porcine embryos were enzymatically dispersed to form single cell suspensions, then allowed to plate in 25 cm(3) tissue-culture flasks.

Ovarian response to active immunization against luteinizing hormone in the cow.

Two experiments were conducted to determine whether active immunization against luteinizing hormone (LH) could lead to ovarian cyst development in the cow. In Experiment 1, cyclic beef heifers were randomly assigned to receive bovine LH (bLH) conjugated with ovalbumin (LH-immunized; n=4) or ovalbumin alone (control; n=5). Blood samples were collected at monthly intervals from the LH-immunized heifers to determine antibody titers.

Development of one-cell ovine embryos in two culture media under two gas atmospheres.

The objective of this study was to develop a successful system for culturing one-cell ovine embryos through several cleavage divisions. One hundred and four one-cell embryos were collected from synchronized, FSH-treated ewes 48 hr after the onset of estrus and randomly placed in one of four culture treatments. The effect of glucose supplementation and reduced oxygen tension (20% vs.

Observations on the in vitro formation, development and differentiation of trilaminar vesicles formed from enzymatically dispersed porcine blastocysts.

The formation of trophoblastic vesicles and their use as a model for cell-to-cell interactions in the embryonic development of the mouse have been extensively studied both in vitro and in vivo . In this report, we describe the formation of trilaminar vesicles in vitro from enzymatically dispersed porcine blastocysts. Trilaminar vesicles were generated from single cell suspensions of enzymatically dispersed porcine blastocysts recovered 12 through 15 days post-breeding.

Transrectal real-time ultrasound scanning of the cow reproductive tract.

A transrectal real-time ultrasound scanning of the cow reproductive tract allows the operator to view images of structures which normally can be only palpated. The device used in these studies allowed exact evaluation of the cow reproductive tract for position, size and consistency of ovaries, uterus and fetuses; these parameters cannot be described to this level of exactness even by the most skilled palpators. This paper describes real-time ultrasound scanning of an ovary containing a cystic corpus luteum and several follicles and ofa nonpregnant and a pregnant tract at different stages of gestation.

Comparative role of vitamin A and beta-carotene on reproduction and neonate survival in rats.

Female rats were used to investigate the comparative role of vitamin A and beta-carotene (dietary or injected) on growth, feed intake and reproduction. After 3 wk of vitamin A and beta-carotene depletion, rats were assigned to one of six groups: 1) CON = fed 5% NRC recommended level of vitamin A (= 60 mug retinol equivalent (RE)/kg diet); 2) VA = fed 100% of vitamin A (= 1200 mug RE/kg diet); 3) HVA = fed 150% of vitamin A; 4) VA+C = fed 100% of vitamin A + 1.2mg beta-carotene; 5) VA+IC = fed 100% of vitamin A + injected weekly with 8.