Do reproducing female reptiles adaptively manipulate phenotypic traits of their offspring by selecting appropriate nest sites? Evidence to support this hypothesis is indirect, mostly involving the distinctive characteristics of used (vs. available) nest sites, and the fact that physical conditions during egg incubation can modify hatchling phenotypic traits that plausibly might influence fitnes...

Growth is one of the most economically important traits in the poultry industry. In this study, we identified single-nucleotide polymorphisms (SNPs) and candidate genes associated with growth traits of the Jinghai Yellow chicken. Genome-wide association studies were conducted using the Illumina 60 K SNP Chicken array to genotype 400 Jinghai Yellow chickens. For each bird, the body weights at ha...

Improvements in the duration of fertility (DF) could increase the interval between successive artificial inseminations, thereby decreasing the cost associated with production of hatching eggs. The molecular mechanisms involved in DF in hens remains under-explored. In this study, expression levels of the transforming growth factor-β genes (TGFβs: TGFβ1, TGFβ2, TGFβ3) were investigated in utero-v...

Chicks from 0 to 61 days post-hatching were gently folded into the hatching position and placed in artificial glass eggs. Within 0 to 2 min they began to produce a behavior that qualitatively resembled normal hatching. Furthermore, quantitative analysis of electromyographic records showed that under these conditions the intralimb and interlimb leg motor output patterns produced during each hatc...

Under the current ocean warming scenario, multigenerational studies are essential to address possible adaptive changes in phenotypic traits of copepod populations. In this study, we exposed calanoid Paracartia grani, reared laboratory at 19°C, warmer conditions (22°C and 25°C) investigate key 1st, 10th, 11th generations. Development rates adult body size were inversely related temperature all W...

Fertility is fundamental to reproductive success, but not all copulation attempts result in a fertilized embryo. Fertilization failure especially costly for females, we still lack clear understanding of the causes variation female fertility across taxa. Birds make useful model system research, partly because their large eggs are easily studied outside female's body, also wealth data available o...

The effects of supplementing a basal diet with 2 levels of an essential oil mixture and an antibiotic on the growth, laying traits, and egg hatching characteristics of broiler breeders were examined in this study. Nine hundred sixty female and 128 male breeders at an age of 1 d old were randomly allocated to 16 replicates (i.e., 4 replicates of 4 dietary treatments) in a floor pen trial. Two le...

The timing of life-history events in insects can have important consequences for both survival and reproduction. For insect herbivores with complex life histories, selection is predicted to favor those combinations of traits that increase the size at metamorphosis while minimizing the risk of mortality from natural enemies. Studies quantifying selection on life-history traits in natural insect ...