Impact of mother genetic and resource environment on her offspring’s growth features in Munjal sheep

Summary The present study evaluated maternal and additive influences that contribute to phenotypic variation in various growth traits in Munjal sheep. The targeted traits that pertained to 2278 records of 706 lambs were birth weight (BWT), weaning weight (WT3), 6-month body weight (WT6), 12-month body weight (WT12), average daily gain (ADG1: 0–3 months; ADG2: 3–6 months, ADG3: 6–12 months of age) and their corresponding Kleiber ratios designated as KR1, KR2 and KR3. The direct heritability estimates for BWT, WT3, WT6, WT12, ADG1, ADG2, ADG3, KR1, KR2 and KR3 under animal models were 0.20 ± 0.08, 0.28 ± 0.08, 0.17 ± 0.07, 0.47 ± 0.09, 0.33 ± 0.08, 0.09 ± 0.06, 0.36 ± 0.10, 0.33 ± 0.08, 0.09 ± 0.06 and 0.32 ± 0.10, respectively. The estimates of maternal genetic effects contributed significantly and were 8% and 7% for BWT and WT3 traits, respectively, which highlighted the considerable role of maternal effects on early growth traits. Genetic and phenotypic correlations ranged from moderate to high between weaning and post-weaning traits. It was concluded that early selection that considered additive as well as maternal effects at weaning age may be delivered to the desired genetic progress in Munjal sheep.

Reciprocal interactions between aphids and arbuscular mycorrhizal fungi across plant generations

The conditions experienced by one plant generation can influence the growth of the offspring generation. These maternal effects can reduce performance of foliar-feeding insects, through accumulation of plant defences. Arbuscular mycorrhizal fungi (AMF) inhabit the roots of plants and are known to influence the performance of foliar-feeding insects. However, all published studies of the interactions between insects and AMF have taken place within one plant generation, but none across generations. Thus, in the present study, Senecio vulgaris plants were grown with or without aphids and AMF (termed ‘induction events’), and seeds from each treatment were used to grow plants experiencing that same treatment over four successive generations, all grown in identical environmental conditions. Naïve aphids were reared on Senecio plants whose parents had experienced 0, 1, 2 or 3 induction events. We found strong negative maternal effects of herbivory on aphid growth, which were not mitigated by the mycorrhiza. However, teneral weight and growth rate showed a gradual recovery; aphids reared on plants whose previous three generations suffered attack were similar in size to those at the beginning of the study. Herbivory had positive or negative effects on the mycorrhiza, dependent upon the number of previous generations suffering attack or having mycorrhizal associations. We conclude that the outcome of many insect plant fungal experiments is likely to have been influenced by and need to account for maternal effects of the parental plant’s growth conditions.

Prevalence and Maternal Effects of Hypothyroidism in Pregnancy

Background: Thyroid disorders are among the common endocrine problems in pregnant women. It is now well established that not only overt but subclinical thyroid dysfunction also has adverse effects on maternal and fetal outcome. There are few data from Bangladesh about the prevalence of thyroid dysfunction in pregnancy. With this background, this study aims to find prevalence of thyroid dysfunction in pregnancy and its impact on obstetrical outcome. Materials and methods: It is an observational study done in a Combined Military Hospital (CMH) Chattogram during the period from February to December 2020 on 130 hypothyroid mothers to observe maternal effects of hypothyroidism. Patients were collected as per inclusion and exclusion criteria after informed written consent. Data was compiled and analyzed and presented. Results: Among 1148 total patients,1018(89%) were normal and 130(11%) were diagnosed as hypothyroid.Among all the patients, 35% patientsare from inside the Chattogram and 65% are from outside. Among 130 hypothyroid cases age range revealed 20-45 years and 20 -30 years age group were 82(63.07%), 30-40 years age group was 40(30.76%) and >40 years age group were 8(6.15%). Primigravida was 48(36.92%) cases and multigravida was 82(63.08%) cases, anemia was present in 40(30.76%) cases, 10(7.69%) patients had hypertension, GDM and DM was found in 20(15.38%)and 3(2.30%) cases respectively, preconception hypothyroidism was found in 10(7.69%) and on Levothyroxine during ANC was 120(92.30%).Among all, 63(48.46%) cases were underwent vaginal delivery and 67(51.53%) cases underwent cesarean section. Untreated and irregular treatment in hypothyroidism are associated with pregnancy complications like spontaneous miscarriage 40(30.76%), maternal anaemia 55(42.30%), pre-eclampsia 4(3.07%), pre term birth 16(12.30%), postpartum haemorrhage 3(2.30%). Conclusion: Hypothyroidism is a common clinical condition during pregnancy and it causes variable pregnancy outcome Chatt Maa Shi Hosp Med Coll J; Vol.20 (2); July 2021; Page 18-21

Maternal effects on early-life gut microbiome maturation in a wild nonhuman primate

Early-life gut microbial colonization is an important process shaping host physiology, immunity and long-term health outcomes in humans and other animals. However, our understanding of this dynamic process remains poorly investigated in wild animals, where developmental mechanisms can be better understood within ecological and evolutionary relevant contexts. Using 16s rRNA amplicon sequencing on 525 fecal samples from a large cohort of infant and juvenile geladas (Theropithecus gelada), we characterized gut microbiome maturation during the first three years of life and assessed the role of maternal effects in shaping offspring microbiome assembly. Microbial diversity increased rapidly in the first months of life, followed by more gradual changes until weaning. As expected, changes in gut microbiome composition and function with increasing age reflected progressive dietary transitions: in early infancy when infants rely heavily on their mother's milk, microbes that facilitate milk glycans and lactose utilization dominated, while later in development as graminoids are progressively introduced into the diet, microbes that metabolize plant complex polysaccharides became dominant. Furthermore, the microbial community of nursing infants born to first-time (primiparous) mothers was more "milk-oriented" compared to similarly-aged infants born to experienced (multiparous) mothers. Comparisons of matched mother-offspring fecal samples to random dyads did not support vertical transmission as a conduit for these maternal effects, which instead could be explained by slower phenotypic development (and associated slower gut microbiome maturation) in infants born to first-time mothers. Together, our findings highlight the dynamic nature of gut colonization

Ovipositor sources for queen-rearing of honey bee (Apis mellifera) revealed inheritable maternal effect on reared queen

Queen is arguably the most important member of a honey bee colony, and queen quality is crucial for honey bee colony growth and development. In this study, queens were reared with eggs laid in queen cells (QE), eggs laid in worker cells (WE) and 2-day old larvae in worker cells (L). Those physiological indexes (the weight, thorax size and number of ovarioles) of newly reared queens in each group were measured. Moreover, the reproductive potential of the newly reared queens and foraging ability of worker bees laid by the newly reared queens in each group were further explored. In addition, we also examined whether maternal effects would be transmitted to the offspring queens in honey bee. We found that the weight, number of ovarioles and thorax weight of newly emerged queens in QE were significantly higher than those in WE and L, suggesting the reproductive potential was stronger in QE group than WE and L group. Furthermore, offspring worker bees and queens of QE queens had higher weight at emergence than those from the other two groups. This study proved profound honey bee maternal effects on queen quality, which can be transmitted to their offspring. Our results of the present study were important for improving queen quality and promoting the development of beekeeping and agriculture.

PSVIII-4 Genetic evaluation of functional heifer longevity in north American angus cattle

The goals of this study were to develop a genetic evaluation system for a novel trait called functional heifer longevity (FHL), and determine if this novel trait is heritable. The FHL trait was defined as binary, in which the heifers received the code 1 if they had calved by the end of their third year (n = 377,938), or 0 if they were culled/sold during this period (n = 368,308). Analysis were performed using linear animal models and Bayesian inference. The significant systematic effects included in the statistical models are born by embryo transfer, year-season of birth, and age at calving (in months). Three models, differing according to their random effects (i.e., reduced model, which included only herd-year-season and additive genetic random effects; maternal genetic model, which added maternal genetic effects; and complete model, which further added maternal permanent environmental effects), were compared based on the deviance information criterion (DIC) and the estimates of genetic parameters. The reduced model was preferred according to the DIC values. However, high maternal heritabilities were estimated using the maternal genetic (0.51) and complete (0.36) models, indicating that maternal effects can impact the selection of heifers for breeding. Similar additive genetic heritabilities were estimated among the three models (0.24, 0.27, and 0.25 using the reduced, maternal genetic, and complete models, respectively), and no significant re-ranking of selection candidates were observed based on their additive genetic breeding values. Total heritabilities and correlations estimated between additive genetic and maternal genetic effects were 0.37 and -0.28 for the maternal genetic, and 0.31 and -0.27 for the complete model, respectively. This study shows that FHL is heritable, and that including maternal effects in the statistical models might be important. These results contribute to a larger project studying the genetics of female longevity in Angus cattle.

PSXI-9 Heterotic and breed effects in crossbred lambs

Given its benefits on animal performance, crossbreeding is common commercially. Genetic evaluation of sheep in the U.S. is performed within breed type (terminal, maternal wool, range, hair). While incorporating crossbred records may improve assessment of purebreds, it requires accounting for heterotic and breed effects in the evaluation. The objectives were to i) determine the generalized effects of direct and maternal heterosis on growth traits of crossbred lambs, and ii) estimate covariance components for direct and maternal additive, and uncorrelated maternal environmental, effects among those traits. Data included body weights (BW) at birth (BN; n = 14395), pre-weaning (WN; n = 9298), weaning (WW; n = 9230), and post-weaning (PW; n = 1593). Mean (SD) BW were 5.3 (1.1), 22.2 (8.7), 39.1 (7.2), and 54.2 (8.7) kg for BN, WN, WW, and PW, respectively. Estimates of heterotic effects and covariance components were obtained using a multiple trait animal model. Genetic effects based on founders’ breeds were included, being significant. Estimates of direct heterosis were 3.04 ± 0.61, 2.62 ± 0.64, 3.99 ± 0.54, and 5.97 ± 0.86%, and estimates of maternal heterosis were 1.86 ± 0.87, 4.42 ± 0.79, 3.69 ± 0.66, and 3.77 ± 0.90%, for BN, WN, WW, and PW, respectively. Direct heritability estimates were 0.17 ± 0.02, 0.13 ± 0.02, 0.18 ± 0.02, and 0.47 ± 0.04 for BN, WN, WW, and PW, respectively. Additive maternal effects defined trivial variation in PW. For BN, WN, and WW, respectively, maternal heritability estimates were 0.17 ± 0.02, 0.10 ± 0.02, and 0.07 ± 0.02. Uncorrelated maternal effects defined little variation in any trait. Direct and maternal heterosis had considerable impact on growth traits, emphasizing the value of crossbreeding and the need to account for heterosis, in addition to breed effects, if crossbred lamb information is included in genetic evaluation.