Influence of somatic cell donor breed on reproductive performance and comparison of prenatal growth in cloned canines

Using in vivo–flushed oocytes from a homogenous dog population and subsequent embryo transfer after nuclear transfer, we studied the effects of donor cells collected from 10 different breeds on cloning efficiency and perinatal development of resulted cloned puppies. The breeds were categorized into four groups according to their body weight: small (≤9 kg), medium (>9–20 kg), large (>20–40 kg), and ultra large (>40 kg). A total of 1611 cloned embryos were transferred into 454 surrogate bitches for production of cloned puppies. No statistically significant differences were observed for initial pregnancy rates at Day 30 of embryo transfer for the donor cells originated from different breeds. However, full-term pregnancy rates were 16.5%, 11.0%, 10.0%, and 7.1% for the donor cells originated from ultra-large breed, large, medium, and small breeds, respectively, where pregnancy rate in the ultra-large group was significantly higher compared with the small breeds (P < 0.01). Perinatal mortality until weaning was significantly higher in small breeds (33.3%) compared with medium, large, or ultra-large breeds where no mortality was observed. The mean birth weight of cloned pups significantly increased proportional to breed size. The highest litter size was examined in ultra-large breeds. There was no correlation between the number of embryo transferred and litter size. Taken together, the efficiency of somatic cell cloning and fetal survival after embryo transfer may be affected significantly by selecting the appropriate genotype.     

Effects of melatonin and plane of nutrition on mammary development in prepubertal Boutsiko mountain breed ewe lambs

The effects of melatonin (implants, M or no implants, C) and plane of nutrition (high, H or low, L) on mammary development and growth hormone (GH) concentrations were investigated in prepubertal Boutsiko mountain breed ewe lambs. Eighty female lambs were assigned to each of 4 treatments: ad libitum feeding control (HC), HM, LC and LM. The rearing treatments started and ended at mean ages of 63 and 160 d, respectively. Feed restriction resulted in a mean daily gain of 70.6% of the ad libitum-fed lambs during the experimental period. Melatonin (18 mg Regulin) was administered at 68 d of age (January 10) and replaced on March 1. Blood samples were collected from 10 lambs in each treatment group at the end of the experiment for GH measurements. At a mean age of 160 d, seven lambs from each treatment group were slaughtered and the udder was removed. One udder half was trimmed and the parenchyma and fat pad portions were kept for determination of deoxyribonucleic acid (DNA) content. Melatonin did not influence mammary development parameters, while the mass of parenchyma tended to be greater in lambs on low than high nutrition planes (P<0.10). Mean mammary parenchymal weight and DNA content were 25.1 and 29.2 g and 52.5 and 58.2 mg in high and low nutrition lambs, respectively. Mean plasma GH concentrations were not affected by melatonin treatment and were higher in low than high nutrition lambs (P<0.01). There were no correlations between mean plasma GH concentrations and parenchymal DNA content, or between mean daily weight gain and parenchyma (g), in contrast to those found in a previous experiment with lambs of the same breed but greater age at slaughter. The results suggest that a period of accelerated mammary development occurs later than 140 d of age in Boutsiko mountain breed ewe lambs.     

Effects of ascorbic acid supplementation on male reproductive system during exposure to hypoxia

Two groups of male rats were exposed to simulated altitudes of 6060 m and 7576 m for 6 h/day for 7 days (intermittent exposure). In two additional groups of animals exposed to the same altitude, 100 mg of ascorbic acid (AA) was fed daily for 5 days prior to the exposure period and also during the exposure period. Rats that did not receive AA showed loss of body weight and weight of reproductive organs after exposure. Sex organs showed atrophy on histological examination and there was a deterioration in spermatozoal quality. There was an increase in alkaline and acid phosphatase, and decrease in protein, sialic acid and glyceryl phosphorylcholine content in various reproductive tissues after exposure. All the above changes in histology and biochemical composition could be partially prevented by AA supplementation. AA supplementation can therefore protect the male reproductive system from deleterious effects of hypoxia. The probable mechanism of action of AA is discussed.     

Effects of ectoparasite infestation during pregnancy on physiological stress and reproductive output in a rodent-flea system

Biotic and abiotic stressors impose various fitness costs on individuals across a variety of taxa. In vertebrates, these stressors typically trigger complex neuroendocrine responses that stimulate glucocorticoid (GC) secretion from the adrenal cortex. Short-term elevation of GCs can be adaptive as it shifts energy toward physiological processes that cope with acute stressors; however, chronic increases in GC levels could have detrimental effects on fitness. Parasitism can be considered an important biotic stressor in nature and a possible cause of reproductive failure that could substantially affect an individual’s fitness. Thus, we aimed to test the effects of parasitism and maternal stress, as measured by GCs, during pregnancy and the relationship between these variables and measures of reproductive output using a rodent-flea system. Female Egyptian spiny mice (Acomys cahirinus) were randomly assigned to flea (Parapulex chephrenis) infested or uninfested treatments before and during pregnancy. The offspring of these females were flea-free. Feces were collected at five time points during the experiment to determine maternal fecal glucocorticoid metabolite (FGCM) concentrations. Overall, infested females had lower FGCM levels during gestation but higher FGCM levels post-parturition and larger mass changes than uninfested females. Additionally, models related to pup quality and quantity often included some measure of maternal investment or body condition moderating relationships between infestation and stress. This suggests that flea parasitism or high GC levels alone might not significantly impact host reproduction but rather females can experience different effects depending on their level of investment, which could be limited by body condition and/or the number of pups present in a litter.     

Effects of cocaine hydrochloride on the male reproductive system

The reproductive system effects of cocaine were studied in male rats. The analysis included measurements of circulating levels of luteinizing hormone (LH) and testosterone (T) by radioimmunoassay (RIA). The weights of the testes and sex accessory organs were also assessed and compared with control animals. Dosage level, duration of treatment, and interval between injection and sacrifice were the parameters examined. Following a single intraperitoneal (IP) injection, LH levels decreased over a 3-hour period. At a high dosage (40 mg/kg), cocaine caused a significant elevation in serum T followed by a significant depression of T for at least 2 hours. When administered chronically for 15 days, the low dose group (10 mg/kg) did not vary significantly from the vehicle controls. However, the high dose group had lower LH and T levels, as well as correspondingly lighter weight seminal vesicles and epididymis. No changes were noted in the weights of the ventral prostate or testes. This research suggests that cocaine acts primarily at the hypothalamic-hypophyseal axis with a possible secondary action at the gonadal level.     

Effects of varied nitrogen stress on growth and nutrition in three Salix clones

The ability of Salix aquatica Smith, S. fragilis L. and S. viminalis L. to absorb nitrogen at varied growth rates was investigated in nutrient solutions. The effects of five nitrogen addition rates on growth rates, nitrogen contents of the plants, nitrogen concentration of the media, and dry matter distribution between roots, stems and leaves, were studied.
These clones are highly efficient in absorbing nitrogen at low concentrations in the root medium, independent of growth rate. Strong linear regressions were found between any two of the three factors: relative rate of nitrogen supply (R_N), nitrogen content (plant), and relative growth rate (R). Dry matter production per unit nitrogen taken up and unit time (N-productivity) and per unit nitrogen taken up independent of time (N-efficiency) was closely correlated to the nitrogen status of the plant. Root development was favoured in the sub-optimum treatments, and leaf development in the optimum treatments. With regard to their ability to absorb nitrogen, these Salix clones appear satisfactory for efficient short rotation energy forestry.     

Effects of boron foliar applications on vegetative and reproductive growth of sunflower

Foliar application may be used to supply boron (B) to a crop when B demands are higher than can be supplied via the soil. While B foliar sprays have been used to correct B deficiency in sunflower (Helianthus annuus L.) in the field, no studies have determined the amount of B taken up by sunflower plant parts via foliar application. A study was conducted in which sunflower plants were grown at constant B concentration in nutrient solution with adequate B (46 micro m) or with limited B supply (0.24, 0.40 and 1.72 micro m) using Amberlite IRA-743 resin to control B supply. At the late vegetative stage of growth (25 and 35 d after transplanting), two foliar sprays were applied of soluble sodium tetraborate (20.8 % B) each at 0, 28, 65, 120 and 1200 mm (each spray equivalent to 0, 0.03, 0.07, 0.13 and 1.3 kg B ha-1 in 100 L water ha-1). The highest rate of B foliar fertilization resulted in leaf burn but had no other evident detrimental effect on plant growth. Under B-deficient conditions, B foliar application increased the vegetative and reproductive dry mass of plants. Foliar application of 28-1200 mm B increased the total dry mass of the most B-deficient plants by more than three-fold and that of plants grown initially with 1.72 micro m B in solution by 37-49 %. In this latter treatment, the dry mass of the capitulum was similar to that achieved under control conditions, but in no instance was total plant dry mass similar to that of the control. All B foliar spray rates increased the B concentration in various parts of the plant tops, including those that developed after the sprays were applied, but the B concentration in the roots was not increased by B foliar application. The B concentration in the capitulum of the plants sprayed at the highest rate was between 37 and 93 % of that in the control plants. This study showed that B foliar application was of benefit to B-deficient sunflower plants, increasing the B status of plant tops, including that of the capitulum which developed after the B sprays were applied.     

Biotin deficiency and biotin excess: Effects on the female reproductive system

Biotin deficiency and biotin excess have both been found to affect reproduction and cause teratogenic effects. In the reproductive tract, however, the effects of biotin have not been well established yet. We investigated the effects of varying biotin content diets on the oestrus cycle, ovarian morphology, estradiol and progesterone serum levels, and the uterine mRNA abundance of their nuclear receptors, as well as on the activity of the estradiol-degrading group of enzymes cytochrome P450 (CYP) in the liver. Three-week-old female BALB/cAnN Hsd mice were fed a biotin-deficient, a biotin-control, or a biotin-supplemented diet (0, 7.2 or 400 μmol of free biotin/kg diet, respectively) over a period of nine weeks. Striking effects were observed in the biotin-deficient group: mice showed arrested estrous cycle on the day of diestrus and changes in ovary morphology. Estradiol serum concentration increased 49.2% in biotin-deficient mice compared to the control group, while the enzymatic activities of CYP1A2 and CYP2B2 increased (P < 0.05). The mRNA abundance of nuclear estrogen and progesterone receptors decreased in the biotin-deficient mice. In the biotin-supplemented group we found that, in spite of a significant (P < 0.05) decrease in the number of primary and Graafian follicles and in CYP1A2 activities, mice exhibited 105.4% higher serum estradiol concentration than the control group. No changes in the expression of the nuclear receptors were observed. No significant differences were observed in serum progesterone among the groups. Our results indicate that both the deficiency and the excess of biotin have significant effects on the female mouse reproductive system.     

Biotin deficiency and biotin excess: Effects on the female reproductive system

Biotin deficiency and biotin excess have both been found to affect reproduction and cause teratogenic effects. In the reproductive tract, however, the effects of biotin have not been well established yet. We investigated the effects of varying biotin content diets on the oestrus cycle, ovarian morphology, estradiol and progesterone serum levels, and the uterine mRNA abundance of their nuclear receptors, as well as on the activity of the estradiol-degrading group of enzymes cytochrome P450 (CYP) in the liver. Three-week-old female BALB/cAnN Hsd mice were fed a biotin-deficient, a biotin-control, or a biotin-supplemented diet (0, 7.2 or 400 μmol of free biotin/kg diet, respectively) over a period of nine weeks. Striking effects were observed in the biotin-deficient group: mice showed arrested estrous cycle on the day of diestrus and changes in ovary morphology. Estradiol serum concentration increased 49.2% in biotin-deficient mice compared to the control group, while the enzymatic activities of CYP1A2 and CYP2B2 increased (P < 0.05). The mRNA abundance of nuclear estrogen and progesterone receptors decreased in the biotin-deficient mice. In the biotin-supplemented group we found that, in spite of a significant (P < 0.05) decrease in the number of primary and Graafian follicles and in CYP1A2 activities, mice exhibited 105.4% higher serum estradiol concentration than the control group. No changes in the expression of the nuclear receptors were observed. No significant differences were observed in serum progesterone among the groups. Our results indicate that both the deficiency and the excess of biotin have significant effects on the female mouse reproductive system.     

Effects of lanthanum and cerium on the growth and mineral nutrition of corn and mungbean

Background and Aims: Plant growth responses to the rare earth elements lanthanum(La) and cerium (Ce) have been reported, but little is knownabout the effects of these two elements on plant mineral nutrition. Methods: Corn (Zea mays ‘Hycorn 82’) and mungbean (Vignaradiata ‘Berken’) were grown in continuous flowingnutrient solutions containing 0, 0·2, 1·0 and5·0 µM La or Ce. At harvest plants were dividedinto roots and shoots, dried, weighed and analysed for macro-and micronutrients, as well as for La and Ce. Key Results: La and Ce did not increase the growth of corn or mungbean. Thedry weight of corn shoots was decreased by 32 % in the presenceof 5·0 µM Ce; the other La and Ce concentrationshad no effect. La and Ce concentrations of 0·9 and 5·0µM decreased the shoot dry weight of mungbean by 75 or95 %, the two elements having closely similar effects. Decreasesin the uptake of Ca, Na, Zn and Mn by corn were observed withincreases in solution La and Ce. For mungbean, the uptake ratesof all measured elements decreased with increases in solutionLa and Ce. The concentrations of La and Ce in the roots of bothspecies were higher than in the shoots and increased stronglywith increasing concentrations of La or Ce in solution. TheLa and Ce concentrations in mungbean shoots were always higherthan in corn shoots. Conclusions: La and Ce did not enhance the growth of corn or mungbean, butdecreased the growth, root function and consequently the nutritionalstatus of mungbean at concentrations >0·2 µMin solution. It is concluded that if La or Ce have positiveeffects on corn and mungbean growth, they can only occur atsolution concentrations below 0·2 µM.     

Effects of furazolidone on some reproductive hormones during oestrous cycle in the goat

In non-pregnant goat luteolysis is characterized by a decline in peripheral plasma progesterone level and increased peripheral plasma concentrations of testosterone (T) and 5 alpha-dihydrotestosterone (DHT). Daily oral doses of furazolidone (80 mg/kg) between days 10 and 16 delayed luteolysis and suppressed both the decline in progesterone concentrations and the increase in T and DHT level.     

Effect of dose rate and exposure time on the stimulation effect of tube growth ofPinus Silvestris pollen

The stimulating effect of ionizing radiation in respect to dose rate and exposure time was studied using the tube growth of Pinus silvestris pollen. Stimulation was registered with a small dose (50 rad) supplied at low dose rates (0.5; 1.0; 3.0 and 5.0 rad/sec) and with higher doses (300, 800 and 1400 rad) supplied at higher dose rates (10; 40 and 50 rad/sec). This suggests that only the exposure time is of importance for radiation-induced stimulation provided that the exposure time does not exceed 100 sec.     

The role of oxidative stress in developmental and reproductive toxicity of tamoxifen

The antiestrogen tamoxifen (TAM) is widely used as a drug against breast cancer and is currently being tested as a chemopreventive agent. However, a number of studies showed genotoxic and carcinogenic effects of TAM. These effects are thought to be related to oxygen radical overproduction which occurs during TAM metabolic activation. There is no evidence, thus far, on TAM toxicity to embryos and gametes. The present study was designed to elucidate the mechanisms of TAM-induced developmental, reproductive and cytogenetic toxicity towards sea urchin (SU) embryos with regard to the possibility of TAM-initiated oxidative stress. Embryo cultures from SU were subjected to long-term (throughout embryogenesis) or short-term (two hours) incubation with TAM at concentrations from 10(-8) to 10(-5) M. The experiments on TAM-induced toxicity to gametes were carried out with SU sperm, or unfertilized eggs, suspended in TAM (10(-8) to 10(-6) M). To assess the effects of TAM to embryos or to gametes, developmental defects, embryonic mortality, fertilization success, and cytogenetic abnormalities were scored. Oxidative damage to DNA and lipids was detected by measurements of 8OHdG levels and lipid peroxidation, respectively. Reactive oxygen species (ROS) production by eggs and embryos was recorded by luminol-dependent chemiluminescence (LDCL) and cytochrome c reduction methods. The changes in activities of SU superoxide dismutase (SOD) and catalase were also evaluated. TAM exerted: a) early embryonic mortality to exposed embryos and to the offspring of exposed eggs; b) developmental defects to the offspring of exposed sperm; c) decrease in sperm fertilization success, and d) cytogenetic effects in the offspring of exposed sperm or eggs. These morphological effects corresponded to the state of oxidative stress in SU embryos (increased oxidative damage to DNA and lipids and induction of antioxidant enzymes). Since TAM did increase significantly ROS production by embryos, it is suggested that TAM may be metabolically activated by SU embryonic oxidases and peroxidases, which in turn could be induced by TAM. The present study provides further support to the utilization of the SU system as a useful model to help elucidate mechanisms of chemical teratogenesis and carcinogenesis.     

Effects of growth hormone overexpression and growth hormone resistance on neuroendocrine and reproductive functions in transgenic and knock-out mice

Transgenic mice overexpressing growth hormone (GH) exhibit alterations in the function of the hypothalamic-pituitary-gonadal (HPG) axis and the H-P-adrenal axis. Alterations in the turnover of hypothalamic neurotransmitters, in plasma hormone levels, and in regulation of their release are associated with reproductive deficits, particularly in females. Results reported after publication of our minireview on this subject provided evidence that GH-transgenic mice have increased binding of GH to GH binding proteins in plasma, are hyperinsulinemic and insulin resistant, and have major alterations in energy budgets with increased allocation to growth. Reduced life span and fertility of these animals may be related to insufficient allocation of energy to reproduction and maintenance. Growth hormone resistance induced by transgenic expression of an antagonistic bGH analog or by targeted disruption (knock-out, KO) of the GH receptor (GH-R) gene leads to dramatic suppression of plasma levels of insulin-like growth factor-1 (IGF-1), and dwarf phenotype due to reduced growth and increased adiposity. In both models of GH resistance, there are marked reproductive deficits in females, decline of breeding performance of males, and alterations in the function of the HPG axis. In GH-R-KO females, puberty is delayed, and litter size is reduced. Fetal weights are reduced whereas placental weights are increased, and the weight of newborn pups is reduced despite an increase in the length of gestation. In GH-R-KO males, copulatory behavior and fertility are reduced, plasma PRL is elevated, and responses to luteinizing hormone releasing hormone (LHRH) in vivo and to LH in vitro are suppressed. However, reproductive deficits in GH-R-KO mice are very mild when compared to those described previously in IGF-KO animals. Apparently, the amounts of IGF-1 that may be produced locally in the absence of GH stimulation are sufficient for sexual maturation and fertility in both sexes, whereas quantitative deficits in reproductive function reflect absence of GH-dependent IGF-1 production and other consequences of eliminating GH signaling. The reproduction phenotype of the GH-R-KO mice is also mild when compared to dwarf mice that lack GH, prolactin (PRL), and thyroid stimulating hormone (TSH). This is presumably related to the presence of redundant mechanisms in the stimulatory control of the gonads by the pituitary and the ability of animals capable of producing PRL and TSH to compensate partially for the absence of GH signaling.     

The effect of mineral nutrition on the growth and maintenance components of respiration during heterotrophic growth of barley seedlings

Spring barley seedling were grown in the dark for 21 d and respiration rates of the whole plant (including the seed), of the shoots, and of the roots were determined. A function describing the growth and maintenance components of respiration was interpolated through the experimental points and its parameters in plants under different mineral nutrition were compared. The plants grown in a complete nutrient solution showed the highest growth rate in the initial phase of development and thus reached the maximum respiration rate earlier than plants in the other variants. The highest proportion of substrate was respired in the shoot. Plants grown under deficiency of phosphorus and magnesium had a slower respiration rate than plants grown in the complete nutrient solution (NP), whereas the amount of respired substrate in plant parts was similar to that recorded in the NP plants. Plants grown in distilled water showed the lowest growth efficiency and respirated the highest proportion of substrate in the root.