Multiple sex pheromones and receptors of a mushroom-producing fungus elicit mating in yeast.
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The mushroom-producing fungus Schizophyllum commune has thousands of mating types defined, in part, by numerous lipopeptide pheromones and their G protein-linked receptors. Compatible combinations of pheromones and receptors encoded by different mating types regulate a pathway of sexual development leading to mushroom formation and meiosis. A complex set of pheromone-receptor interactions maximizes the likelihood of outbreeding; for example, a single pheromone can activate more than one receptor and a single receptor can be activated by more than one pheromone. The current study demonstrates that the sex pheromones and receptors of Schizophyllum, when expressed in Saccharomyces cerevisiae, can substitute for endogenous pheromone and receptor and induce the yeast pheromone response pathway through the yeast G protein. Secretion of active Schizophyllum pheromone requires some, but not all, of the biosynthetic machinery used by the yeast lipopeptide pheromone a-factor. The specificity of interaction among pheromone-receptor pairs in Schizophyllum was reproduced in yeast, thus providing a powerful system for exploring molecular aspects of pheromone-receptor interactions for a class of seven-transmembrane-domain receptors common to a wide range of organisms. (+info)
Effects of active immunization against growth-hormone releasing factor on puberty and reproductive development in gilts.
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Hormones within the somatotropin cascade influence several physiological traits, including growth and reproduction. Active immunization against growth hormone-releasing factor (GRFi) initiated at 3 or 6 mo of age decreased weight gain, increased deposition of fat, and delayed puberty in heifers. Two experiments were conducted to investigate the effects of GRFi on puberty and subsequent ovulation rate in gilts. Crossbred gilts were actively immunized against GRF-(1-29)-(Gly)2-Cys-NH2 conjugated to human serum albumin (GRFi) or against human serum albumin alone (HSAi). In Exp. 1, gilts were immunized against GRF (n = 12) or HSA (n = 12) at 92 +/- 1 d of age. At 191 d of age, antibody titers against GRF were greater (P < .05) in GRFi (55.5 +/- 1.3%) than in HSAi (.4 +/- 2%) gilts. The GRFi decreased (P < .05) BW (86 +/- 3 vs 104 +/- 3 kg) by 181 d of age and increased (P < .05) backfat depth (15.7 +/- .4 vs 14.8 +/- .4 mm) by 130 d of age. At 181 d of age, GRFi reduced the frequency of ST release (1.0 +/- .5 vs 5.0 +/- .5, peaks/24 h; P < .0001) and decreased (P < .01) ST (1.1 +/- .06 vs 1.7 +/- .06 ng/mL), IGF-I (29 +/- 2 vs 107 +/- 2 ng/mL), and insulin concentrations (3.5 +/- .2 vs 6.3 +/- .2 ng/mL). The GRFi decreased (P < .05) feed conversion efficiency but did not alter age at puberty (GRFi = 199 +/- 5 d vs HSAi = 202 +/- 5 d) or ovulation rate after second estrus (GRFi = 10.7 +/- .4 vs HSAi = 11.8 +/- .5). In Exp. 2, gilts were immunized against GRF (n = 35) or HSA (n = 35) at 35 +/- 1 d of age. The GRFi at 35 d of age did not alter the number of surface follicles or uterine weight between 93 and 102 d of age, but GRFi decreased (P < .05) ovarian weight (.41 +/- .08 vs 1.58 +/- .4 g) and uterine length (17.2 +/- 1.1 vs 25.3 +/- 2.3 cm). Immunization against GRF reduced (P < .05) serum IGF-I (GRFi = 50 +/- 4 vs HSAi = 137 +/- 4 ng/mL) and BW (GRFi = 71 +/- 3 vs HSAi = 105 +/- 3 kg) and increased (P < .05) backfat depth (GRFi = .38 +/- .03 vs HSAi = .25 +/- .02 mm/kg). Age at puberty was similar in GRFi and HSAi gilts, but ovulation rate was lower (P < .05) after third estrus in GRFi (11.3 +/- .8) than in HSAi (13.8 +/- .8) gilts. Thus, GRFi at 92 or 35 d of age decreased serum ST, IGF-I, and BW in prepubertal gilts without altering age of puberty. However, GRFi at 35 d of age, but not 92 d of age, decreased ovulation rate. These results indicate that alterations in the somatotropic axis at 1 mo of age can influence reproductive development in pubertal gilts. (+info)
Effects of induced hypothyroidism or hyperthyroidism on growth and reproductive performance of Brahman heifers.
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Prepubertal Brahman heifers (BW = 302 +/- 7.5 kg, body condition score [BCS] = 5.4 +/- .2, age = 498 +/- 3.4 d: SEM) were used to study the effects of thyroid function on growth and reproduction. Seven heifers were controls (C). Seven heifers were induced to become hypothyroid by ingestion of 4 mg/kg BW of 6-n-propyl-2-thiouracil (PTU). Seven heifers were induced to become hyperthyroid (T) by daily s.c. injections of triiodothyronine (T3, 1 mg/d). Treatments were administered for 84 d followed by an 84 d posttreatment period. Blood samples were obtained twice weekly via tail venipuncture for analysis of T3, thyroxine, and progesterone. The BW, BCS, and rectal temperature (RT) were recorded weekly. Estrus was monitored twice daily with the aid of a fertile bull equipped with a chin ball marker. Hyperthyroidism and hypothyroidism were successfully induced in T- and PTU- treated heifers, respectively. During the treatment period, PTU heifers gained the most BW and BCS (72.4 +/- 5.4 kg; .93 +/- .15 units), C heifers were intermediate (41.7 +/- 5.4 kg; .43 +/- .15 units), and T heifers gained the least (13.3 +/- 5.4 kg; -.36 +/- .15 units; P < .05). The RT also decreased (P < .05) in PTU heifers (-1.9 +/- .2 degrees C) compared with C (-1.2 +/- .2 degrees C) or T heifers (-.8 +/- .2 degrees C). No heifers exhibited estrus during the treatment period. During the posttreatment period, T heifers gained the most BW and BCS (93.9 +/- 6.1 kg; 1.14 +/- .13 units), C heifers were intermediate (67.0 +/- 6.1 kg; .86 +/-. 13 units), and PTU heifers gained the least (22.2 +/- 6.1 kg; -.14 +/- .13 units; P < .05). The reversal in BW and BCS gains during the posttreatment period corresponded to periods of transient hypo- and hyperthyroidism in T and PTU heifers, respectively. Age and BW at puberty and pregnancy were similar among all treatment groups. The BCS for T heifers was lower (5.7 +/- .2 units; P < .05) at puberty and pregnancy than for PTU heifers (6.6 +/- .2 units). Induction of hypothyroidism resulted in significant increases in BW and BCS during the treatment period, but these increases were not sufficient to dramatically affect reproductive performance of Brahman heifers. (+info)
Effects of induced hypothyroidism on weight gains, lactation, and reproductive performance of primiparous Brahman cows.
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Primiparous, spring-calving Brahman cows (BW = 425.0 +/- 13.8 kg, body condition score [BCS] = 5.0 +/- .2 units; SEM) were used to study the effects of thyroid manipulation on weight gain, milk production, and reproduction. Nine cows served as controls. Nine cows were induced to become hypothyroid by daily ingestion of 4 mg/kg BW of 6-n-propyl-2-thiouracil (PTU). Cows were stratified to treatment 1 d after calving based on season of birth, BW, BCS, calf sex, and calf sire. The treatment period lasted for 84 d and was followed by a 56-d posttreatment period. Cow BW, BCS, and calf weight were recorded twice weekly. Milk production was estimated at 14, 28, 56, 84, 98, 112, and 140 d after calving. Weekly blood samples were obtained for analysis of triiodothyronine (T3), thyroxine (T4), and progesterone (P4). Estrus was monitored twice daily with the aid of a fertile bull equipped with a chin ball marker. Hypothyroidism was effectively induced in all PTU cows during the treatment period. The PTU cows gained more (P = .002) weight (54.6 +/- 7.6 kg) and tended (P = .06) to increase body condition (.61 +/- .17 units) more than control cows (15.7 +/- 7.6 kg; .11 +/- .17 units) during the treatment period. Control calves gained at a faster rate (.85 +/- .04 kg/d; P < .01) than PTU calves (.70 +/- .04 kg/d) during the treatment period. Milk production was lower (P < .05) in PTU cows on d 56 and 84. During posttreatment all trends were reversed, and BW, BCS, calf weight, and milk production were similar between the two groups by d 140. Reproductive performance was not affected by induction of hypothyroidism. In conclusion, induction of hypothyroidism was successful in increasing cow weight and BCS gains and suppressing milk production during the treatment period, but these changes were not successful in improving reproductive performance of primiparous Brahman cows. (+info)
Human reproductive failure is not a clinical feature associated with beta(2) glycoprotein-I antibodies in anticardiolipin and lupus anticoagulant seronegative patients (the antiphospholipid/cofactor syndrome)
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It has been suggested that patients with clinical features suggestive of antiphospholipid syndrome but being lupus anticoagulant (LA) and anticardiolipin (aCL) negative, should be tested for antibodies to beta(2) glycoprotein-I (abeta(2)GP-I), a protein involved in the binding of antiphospholipid antibodies (aPL) to phospholipid surfaces. This was investigated in the present study where a total of 385 women aged +info)
Blind hemivagina: long-term follow-up and reproductive performance in 42 cases.
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Our purpose was to analyse the reproductive performance of women with obstructed hemivagina after surgical treatment. After laparoscopic exploration of 42 cases (mean age: 18 years), didelphic and complete septate uterus were found in 78 and 22% of cases respectively. Resection of vaginal septum and hemihysterectomy with ipsilateral hemicolpectomy were performed in 88% and 12% of the cases, respectively, between 1970 and 1997. Long-term results were assessed by a questionnaire and obtained for 38 patients (mean years after treatment and range: 6.5; 1-23). Dysmenorrhoea and abdominal pain were resolved in 87% and 100% of the cases, respectively. Nine patients experienced 20 pregnancies (13 living children, four early spontaneous abortions, two early terminations and one ectopic pregnancy). Nine offspring (69% of live births) were delivered after 37 weeks. Four patients had four pregnancies ipsilateral to blind hemivagina after vaginal septum resection (two living children, one early spontaneous abortion and one ectopic pregnancy). These results suggest that laparoscopic exploration and resection of vaginal septum are the appropriate treatments for obstructed hemivagina. Subsequent reproductive performance was comparable to that reported following treatment of the associated uterine malformation. (+info)
Sustained but not repeated acute elevation of cortisol impaired the luteinizing hormone surge, estrus, and ovulation in gilts.
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We tested the hypothesis that sustained and repeated acute elevation of cortisol would impair the LH surge, estrus, and ovulation in gilts. Cortisol was injected intramuscularly, to achieve a sustained elevation of plasma concentrations of cortisol, or intravenously, to achieve an acute elevation of plasma concentrations of cortisol. Control gilts received i.m. injections of oil and i.v. injections of saline. These treatments were administered to gilts (n = 6 per treatment) at 12-h intervals from Days 7 to 11 of the estrous cycle until after estrus ceased or until Day 27 or 28 of the estrous cycle, whichever came first. The repeated acute elevation of cortisol had no effect on the LH surge, estrus, or ovulation. In contrast, when the elevation of cortisol was sustained, the LH surge, estrus, and ovulation were inhibited. We conclude that cortisol is capable of direct actions to impair reproductive processes in female pigs but that plasma concentrations of cortisol need to be elevated for a substantial period for this to occur. (+info)
Maternal effort and male quality in the bank vole, Clethrionomys glareolus.
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Parental investment in reproduction is adjusted according to potential benefits in terms of offspring survival and/or mating success. If male quality affects the reproductive success of a female, then females mating with high-quality males should invest more in reproduction. Although the subject has been of general interest, further experimental verification of the hypothesis is needed. We studied whether female bank voles (Clethrionomys glareolus) adjusted their maternal effort according to male quality, measured as mating success. To enable the measurement of maternal effort during nursing separately from male genetic effects the litters were cross-fostered. Further, the genetic background of male quality was examined. Male quality did not correlate with litter size or offspring size at birth. Offspring growth was positively related to food consumption and milk production of mothers. However, these direct measurements of maternal effort were independent of male quality. Male mating success appeared to be significantly heritable indicating that there are genetic benefits. Still, females did not adjust maternal effort according to the genetic quality of their offspring. We suggest that female bank voles gain significant genetic benefits from mating with high-quality males whereas they cannot improve their reproductive success by increasing maternal effort. (+info)