Differences In Embryos Research Articles

Purification of follicle stimulating hormone from bovine pituitary extracts by monoclonal antibody affinity chromatography

Embryo production is a useful tool for ex situ conservation of endangered species and breeds, despite a high variability in the ovarian response to superovulatory treatments. The current study evaluated the incidence and mechanisms of genetic factors in such variability, by determining the pharmacokinetics and pharmacodynamics of a standard treatment with ovine FSH (oFSH) in two endangered Spanish sheep breeds (Rubia del Molar, R, and Negra de Colmenar, N) in comparison to Manchega ewes (M, control group). In the first experiment, pharmacokinetics of an i.m. single dose of 1.32 mg of oFSH was evaluated in seven animals of each breed. Plasma FSH concentrations reached their maximum at 4 h post-administration in all the ewes, but several of the kinetic parameters (plasma FSH concentration at 4 h post-administration, maximum plasma FSH concentration, Cmax, and both the area under the plasma concentration-time curve extrapolated to the infinite, AUCinf, and to the last moment of sampling, AUClast) were higher in the N group. In the second trial, 10 animals of each breed were superovulated using eight decreasing doses of oFSH (3× 1.32 mg, 2× 1.10 mg, and 3× 0.88 mg). The R group, when compared to N and M, showed both a higher number of corpora lutea (13.7 ± 0.6 versus 10.0 ± 0.4 in N and 9.8 ± 0.6 in M, P < 0.05 for both) and embryos (7.9 ± 0.8 versus 4.3 ± 0.4 in N, P < 0.05, and 6.7 ± 0.5 in M, n.s.). Evaluation of pharmacokinetic and dynamic parameters showed that, although there was a trend for a higher hormone availability in R sheep, mean FSH plasma concentrations were similar between breeds (0.54 ± 0.08 ng/ml for R, 0.45 ± 0.05 ng/ml for N and 0.35 ± 0.05 ng/ml for M). However, differences were found in the number of preovulatory follicles growing in response to the FSH treatment between R (24.4 ± 2.2), M (18.9 ± 1.5, n.s.) and N sheep (14.1 ± 1.4; P < 0.01). Thus, differences in embryo yields between breeds would be related to differences in the pattern of follicular growth in response to FSH treatment.

Developmental Differences in Embryos of High and Low Protein Wheat Seeds during Germination

Developmental patterns of embryos from high and low protein wheat (Triticum aestivum) grain produced under varied fertilizer conditions were compared. High protein grain produced seedlings 25% heavier with 25% more total RNA, 30% more DNA, 40% more amino acids, 60% more ribosomes, and 80% more soluble protein content than that of low protein seed. Consistently higher glutamine synthetase and alpha-amylase and lower acid phosphatase activities were observed in high protein seeds, though the isozyme pattern of alpha-amylase was not different in the two kinds of seeds. The high total ribosomes and particularly, polysome content observed in high protein seeds may be responsible for the rapid growth and high yield of these seeds.

ON THE ENERGETICS OF DIFFERENTIATION. III

The effect of temperature on the rate of development of eggs of Ciona intestinalis, Dendraster excentricus, Urechis caupo, Strongylocentrotus purpuratus and Lytechinus anamesus has been investigated. It is found that not only do the various early cleavage stages have the same temperature coefficient, but the values for the later stages of differentiation are the same as for cleavage.In Ciona, the coefficient for hatching time is different from that for cleavage. An interpretation of this based on the production and diffusion of a hatching enzyme is suggested.Counts of the number of cells of gastrulae of Strongylocentrotus show no significant differences in embryos raised at different temperatures.The data are fairly well expressed by the assumption of a linear relation between the rate of development and temperature.The values of the coefficients for all the forms investigated, with the exception of Strongylocentrotus, are very closely alike, although the rates of development are quite different. Strongylo...