Precocious metamorphosis and wing formation in the pea aphid,Acyrthosiphon pisum,induced by precocene analogue 7-ethoxy-6-methoxy-2,2-dimethylchromene

Maternal treatment with 5 μg of the precocene analogue 7-ethoxy-6-methoxy-2,2-dimethylchromene influenced offspring development in the pea aphid, Acyrthosiphon pisum. Under conditions favoring the production of apterous offspring, virginoparous aphids produced a significant proportion of alates and precocious adultoids; the precocious adultoids were sterile. The effect of precocene on offspring development was temporary. Some implications of precocene treatment for aphid control are discussed.     

Effect of abscisic acid and proline on <Emphasis Type="Italic">in vitro</Emphasis> flowering in <Emphasis Type="Italic">Vigna aconitifolia</Emphasis>

An experiment was taken up to find out possibilities of manipulating the in vitro flowering in moth bean. Abscisic acid (ABA) and proline both alone and in combination influenced days to flower induction, number of flowers per plant, number of pods per plant and seeds per pod. Frequency of flowering plants approached 100 % at 1 and 3 μM ABA and 800 μM proline. The range of flowering period (3 to 23.6 d) has also been influenced by various treatments.     

DNA methylation status of bovine blastocysts obtained from peripubertal oocyte donors

In the dairy industry, the high selection pressure combined with the increased efficiency of assisted reproduction technologies (ART) are leading toward the use of younger females for reproduction purposes, with the aim to reduce the interval between generations. This situation could impair embryo quality, decreasing the success rate of the ART procedures and the values of resulting offspring. Young Holstein heifers (n = 10) were subjected to ovarian stimulation and oocyte collection at 8, 11, and 14 months of age. All the oocytes were fertilized in vitro with semen from one adult bull, generating three pools of embryos per animal. Each animal was its own control for the evaluation of the effects of age. The EmbryoGENE platform was used to compare the DNA methylation status of blastocysts obtained from oocytes collected at 8 versus 14 and 11 versus 14 months of age. Age‐related contrast analysis identified 5,787 and 3,658 differentially methylated regions (DMRs) in blastocysts from heifers at 8 versus 14 and 11 versus 14 months of age, respectively. For both contrasts, the DMRs were distributed nonrandomly in the different DNA regions. The DNA from embryos from 8‐month‐old donors was more hypermethylated, while the DNA from embryos from 11‐month‐old donors displayed an intermediate phenotype. According to Ingenuity Pathway Analysis, the upstream regulator genes cellular tumor antigen p53, transforming growth factor β1, tumor necrosis factor, and hepatocyte nuclear factor 4α are particularly associated with methylation sensitive targets, which were more hypermethylated in embryos from younger donors.     

Variability of some blood serum β-globulins in life cycle of sturgeons (Acipenseridae)

Blood proteins of sturgeons of two genera Acipenser and Pseudoscaphirhynchus preserving unidirectional variability in ontogenesis regardless of peculiarities of the fish ecology have heterochronic character. The slowest ontogenetic development lasting for 4–6 years is peculiar to one of antigens of β-globulins. Analysis of the variability of β-globulins in the age range beginning from the 4-month juveniles and including adult spawned individuals indicates different functional significance of their individual components. The βA-globulin absent at early postembryonic stages becomes the second, after albumin, quantitatively predominant antigen in the adult fish blood. The amount of βB-globulin, like antigens of α₁and α₂-globulins preserving relative ontogenetic stability, can decrease significantly in freshwater sturgeons due to their preparation for spawning.     

Testosterone changes during the period of adolescence in male rhesus monkeys (Macaca mulatta)

Testosterone levels of 59 male rhesus monkeys were monitored over a period of 5 years. Longitudinal comparisons revealed consistent rises in mid-morning levels of circulating hormone in successive years from age 2.5 to 6.5 years of age, whereas cross-sectional comparisons failed to detect significant differences among the older subjects. The first mid-morning hormonal elevation could be detected in some males as young as 2.5 years of age, whereas other males showed no detectable rises until age 5.5 years. Males showing first rises at later ages did not show hormonal levels consistently below age peers who had shown earlier rises. Extreme month-to-month variability and a failure to manifest the seasonal normal curve of fully adult males was characteristic of younger males, but some of these males, nonetheless, proved capable of fertilizing females. Although hormonal and agonistic dominance measures failed to show consistent correlations, the alpha male in an age cohort significantly more often had the highest testosterone levels. These data are used to argue that adolescence is a process that takes place over several years and that classification of adolescent animals as adults, based on a single criterion like fertility, has confounded many prior studies involving cross taxa comparisons as well as developmental variables.