Molecular basis of parental contributions to the behavioural tolerance of elevated pCO 2 in a coral reef fish

Knowledge of adaptive potential is crucial to predicting the impacts of ocean acidification (OA) on marine organisms. In the spiny damselfish, Acanthochromis polyacanthus , individual variation in behavioural tolerance to elevated pCO 2 has been observed and is associated with offspring gene expression patterns in the brain. However, the maternal and paternal contributions of this variation are unknown. To investigate parental influence of behavioural pCO 2 tolerance, we crossed pCO 2 -tolerant fathers with pCO 2 -sensitive mothers and vice versa, reared their offspring at control and elevated pCO 2 levels, and compared the juveniles' brain transcriptional programme. We identified a large influence of parental phenotype on expression patterns of offspring, irrespective of environmental conditions. Circadian rhythm genes, associated with a tolerant parental phenotype, were uniquely expressed in tolerant mother offspring, while tolerant fathers had a greater role in expression of genes associated with histone binding. Expression changes in genes associated with neural plasticity were identified in both offspring types: the maternal line had a greater effect on genes related to neuron growth while paternal influence impacted the expression of synaptic development genes. Our results confirm cellular mechanisms involved in responses to varying lengths of OA exposure, while highlighting the parental phenotype's influence on offspring molecular phenotype.

Dissecting genetic trends to understand breeding practices in livestock: a maternal pig line example

Background Understanding whether genomic selection has been effective in livestock and when the results of genomic selection became visible are essential questions which we have addressed in this paper. Three criteria were used to identify practices of breeding programs over time: (1) the point of divergence of estimated genetic trends based on pedigree-based best linear unbiased prediction (BLUP) versus single-step genomic BLUP (ssGBLUP), (2) the point of divergence of realized Mendelian sampling (RMS) trends based on BLUP and ssGBLUP, and (3) the partition of genetic trends into that contributed by genotyped and non-genotyped individuals and by males and females. Methods We used data on 282,035 animals from a commercial maternal line of pigs, of which 32,856 were genotyped for 36,612 single nucleotide polymorphisms (SNPs) after quality control. Phenotypic data included 228,427, 101,225, and 11,444 records for birth weight, average daily gain in the nursery, and feed intake, respectively. Breeding values were predicted in a multiple-trait framework using BLUP and ssGBLUP. Results The points of divergence of the genetic and RMS trends estimated by BLUP and ssGBLUP indicated that genomic selection effectively started in 2019. Partitioning the overall genetic trends into that for genotyped and non-genotyped individuals revealed that the contribution of genotyped animals to the overall genetic trend increased rapidly from ~ 74% in 2016 to 90% in 2019. The contribution of the female pathway to the genetic trend also increased since genomic selection was implemented in this pig population, which reflects the changes in the genotyping strategy in recent years. Conclusions Our results show that an assessment of breeding program practices can be done based on the point of divergence of genetic and RMS trends between BLUP and ssGBLUP and based on the partitioning of the genetic trend into contributions from different selection pathways. However, it should be noted that genetic trends can diverge before the onset of genomic selection if superior animals are genotyped retroactively. For the pig population example, the results showed that genomic selection was effective in this population.

Effects of restricting energy during the gilt development period on growth and reproduction of lines differing in lean growth rate: Responses in reproductive performance and longevity

Longevity and reproductive performance are economically important traits in the swine industry that are largely influenced by nutrition and other environmental factors. Reproductive performance and longevity through 4 parities was assessed in gilts of 2 genetic lines developed on ad libitum access to feed or restricted to 75% of ad libitum intake. A total of 661 gilts were used in a 2 x 2 factorial with half of the gilts allocated to an ad libitum diet (AL; n = 330), while the other half were energy restricted by 25% (R; n = 331) from 123 to 235 d of age. All gilts were sired by an industry maternal line. Dams of the gilts were from either a Large White by Landrace industry maternal line or Nebraska Selection Line 45X, producing gilts designated as W x L (n = 355) and L45X (n = 306), respectively. Daily estrus detection began at 140 d of age to obtain age at puberty (AP). Gilts (n = 510) were mated on their second or later estrus, beginning at 240 d of age. Sow weight and backfat were recorded at 110 d of gestation and weaning of each parity. Number of live-born, stillborn, and mummified pigs per litter and piglet birth and weaning weights were recorded through 4 parities. More L45X than W x L and more AL than R gilts reached puberty by 230 d of age (P < 0.01). Dietary treatment did not affect probability to produce parities 1 to 4 or any litter trait analyzed. The L45X females tended to be more likely to produce parities 1 (P < 0.08) and 3 (P < 0.06), while W x L had heavier litters at birth (P < 0.01) and weaning (P = 0.01). Treatment by parity interactions (P < 0.01) existed for weight and backfat prior to farrowing and backfat at weaning, and weight at weaning exhibited a line by treatment by parity interaction (P = 0.04) as R sows had lower weights and backfats in earlier parities, but caught up to AL sows in later parities. A treatment by parity interaction (P < 0.01) was also present for backfat loss from farrowing to weaning as R gilts lost less backfat than AL in parities 1 and 2, but more in parities 3 and 4. No significant differences were detected between lines or treatments for lifetime production traits. The populations of pigs and data presented here provide a framework for a diverse array of further studies. Alternative approaches to restrict energy have been assessed in addition to methods of marker-assisted and genomic selection for improvement of litter size and sow longevity.

Sunflower hybrid Status

The widespread saturation of crop rotations with sunflower crops contributed to the creation of favorable conditions for the emergence and wide distribution of new more aggressive races of broomrape, downy mildew and other pathogens of this crop. Sunflower varieties and hybrids resistant to previously common races have become severely affected. One of the ways to solve this problem is to develop sunflower hybrids resistant to new virulent races. The breeders had to combine high productivity and genes of resistance to new more aggressive races of broomrape and downy mildew in one genotype. The first stage of the work was development of a new breeding germplasm and selection of parental lines with breeding valuable traits from it. Based on these lines, there were developed hybrid combinations resistant to new highly virulent races of broomrape and downy mildew. The hybrid Status was developed by hybridization of a maternal line ED 47 and a paternal line ED 193. The maternal line ED 47 is single-headed, low height, resistant to the broomrape races: E, F, G, has a good combining ability. The paternal line ED 193 is branched, also resistant to broomrape (races E, F, G) and three races of downy mildew (330, 710, and 730). The hybrid Status belongs to the middle-early maturity group, duration of the growing season is 95 days. The average plant height over the years of testing was 140 cm; the plants are uniformed in height and the duration of the development phases. Seed yield of the hybrid Status exceeded the standard one (a hybrid Gorstar) by 0.25 t/ha, and oil yield – by 0.14 t/ha. The oil content of the seeds was 48.0%, the huskiness – 28.7%, the 1000 seeds weight – 60.6 g. The new hybrid is resistant to seven races of broomrape (A, B, C, D, E, F, and G) and three races of downy mildew (330, 710, and 730). A distinctive feature of it is resistance of both parent lines to broomrape. The originator of a simple interline sunflower hybrid Status is V.S. Pustovoit All-Russian Research Institute of Oil Crops.

Physico-Chemical, Nutritional, and Sensory Evaluation of Two New Commercial Tomato Hybrids and Their Parental Lines

Tomato (Solanum lycopersicum) is the globally most consumed vegetable. The objective of this research was to analyze physico-chemical, nutritional and sensorial components (taste and flavor) in two new commercial hybrids (AS 300 F1 and AS 400 F1) and their four F7 parental lines. Two widely grown F1 hybrids (Precos F1 and Addalyn F1) were used as controls. The results obtained for carbohydrates (HPLC-RID) indicated that the highest values (27.82 mg/g) were recorded in the paternal line AS 10 of the new hybrid AS 400 F1. The highest values of total organic acids (HPLC-VWD) were recorded in Addalyn F1 (5.06 m/g), while the highest value of phenolic compounds (HPLC-DAD-ESI⁺) were identified in the maternal line AS 09 of the hybrid AS 400 F1 (96.3 µg/g). Intrinsic sensory values were analyzed by male and female tasters of different ages using a hedonic scale. The tasters’ perception revealed obvious taste differences between tomato genotypes. The study allowed determining genetic parameters of interest (heterosis and heterobeltosis) for the new hybrids, as well as a detailed characterization of the chemical composition and organoleptic quality of the parental breeding lines and their hybrids, which is useful in tomato breeding.

PSXV-9 Transgenerational epigenetic variance for production and reproduction traits in maternal-line pigs

Modeling epigenetic factors impacting phenotypic expression of economically important traits has become a hot-topic in the field of animal breeding due to the variability in genetic expression caused by environmental stressors (e.g., heat stress). This variability may be due, in part, to in-utero epigenomic remodeling, which has been reported to be passed from parent to offspring. We aimed to estimate transgenerational epigenetic variance for various production and reproduction traits measured in a maternal-line pig population, using a Bayesian approach. The phenotypes for production [n = 10,862; i.e., weaning weight (WW), birth weight (BW) and ultrasound-backfat thickness (BF)] and reproduction [n = 5,235, i.e., number of piglets born alive (NBA) and total number of piglets born (TB)] traits from a purebred Landrace population were provided by Smithfield Premium Genetics (NC, USA). The pedigree information traced back to 10 generations. Single-trait genetic analyses were performed using mixed models that included additive genetic, common environmental, and epigenetic random effects. The Gibbs sampler algorithm based on Markov chain Monte Carlo was used to estimate the variance components. The epigenetic relationship matrix was constructed using a recursive parameter (λ) related to the transmissibility coefficient of epigenetic markers. A grid search approach was used to define the optimal λ value (λ values ranged from 0.1 to 0.5, with an interval of 0.1). The optimal λ value was determined based on the deviance information criterion, and it was used to estimate the additive and epigenetic variances. For instance, based on preliminary results, the optimal λ value estimated for TB was 0.3 with an additive genetic variance of 0.94 (0.19 PSD) and epigenetic variance of 0.67 (0.18 PSD). The additive genetic heritability was 0.076 (0.015 PSD) and the estimated epigenetic heritability was 0.053 (0.015 PSD). This preliminary result suggests that epigenetics contribute to the non-Mendelian variability in pigs.

PSIV-5 Definition of environmental variables and critical periods to evaluate heat tolerance in maternal-line pigs based on single-step genomic reaction norms

Heat stress (HS) is a major welfare and economic issue in the swine industry. However, it is not a trivial task to appropriately quantify the environmental HS. Therefore, this study aimed to 1) define the critical periods and environmental descriptors (based on public weather station information) to evaluate heat tolerance (HT); and 2) estimate genetic parameters for HT in Large White pigs. The traits included in this study were: weaning weight (WW; kg), off-test weight (OTW; kg), total number of piglets born (TNB), number of piglets born alive (NBA), and number of piglets weaned (WN). The number of phenotypic records ranged from 6,059 (WN) to 172,984 (TNB), and genotypes were available for 8,686 animals. Seven climatic variables (maximum, minimum and average temperatures, average relative humidity, dew point, discomfort index and temperature-humidity index) based on public weather station records were compared based on three criteria [GxE estimate as measured by the slope term; theoretical accuracy of the genomic estimated breeding values (GEBV); deviation of GEBV per environmental value]. Relative humidity (for WN and WW) and maximum temperature (for OTW, TNB, and NBA) are the recommended environmental gradients for the studied traits. The acute HS (average of 30 days before measurement date) was the critical period recommended for OTW. For WN and WW, a period of 34 days prior to farrowing up to weaning is recommended. For TNB and NBA, the critical period of 20 days prior breeding to 30 days into gestation is recommended. In general, WN and WW were largely affected by the environment, while the remaining traits showed moderate correlations (OTW, TNB, and NBA). Heritabilities estimated for HT ranged from 0.08 (WW) to 0.25 (OTW). In summary, these results suggest that there is genotype-by-environment interaction for all traits analyzed, and genetic progress can be achieved through genetic selection.

Mitochondrial Genome (mtDNA) and Human Diseases

Mitochondria not only provide necessary energy for cells, but more importantly, they participate in the regulation of various biological functions and activities of cells. As one of the critical components of the body’s genome, mitochondrial genome (mtDNA) is the key to cell bioenergetics and genetics. However, since no protection of histones and a complete self-repair system, mtDNA is extremely prone to mutate. Human diseases caused by mtDNA mutations are only transmitted through the maternal line. The same phenotype can come from multiple mtDNA mutations, and the same mtDNA mutation can lead to multiple phenotypes. This is the major reason that makes the diagnosis and identification of mtDNA genetic diseases difficult. Meanwhile, mtDNA mutations may be the culprit involved in mediating the aging and tumorigenesis. Currently, no effective therapeutics for diseases caused by mtDNA mutations, but with the deepening of research and technological advancement, it is promising that breakthroughs in the diagnosis and treatment of mitochondrial-related diseases in the near future.

Once We Were Slaves

An obsessive genealogist and descendant of one of the most prominent Jewish families since the American Revolution, Blanche Moses firmly believed her maternal ancestors were Sephardic grandees. Yet she found herself at a dead end when it came to her grandmother’s maternal line. Using family heirlooms to unlock the mystery of Moses’s ancestors, Once We Were Slaves overturns the reclusive heiress’s assumptions about her family history to reveal that her grandmother and great-uncle, Sarah and Isaac Brandon, actually began their lives as poor, Christian, and enslaved in Barbados. Tracing the siblings’ extraordinary journey throughout the Atlantic World, Leibman examines artifacts they left behind in Barbados, Suriname, London, Philadelphia, and, finally, New York to show how Sarah and Isaac were able to transform themselves and their lives, becoming free, wealthy, Jewish, and—at times—white. While their affluence made them unusual, their story mirrors that of the largely forgotten population of people with mixed African and Jewish ancestry that constituted as much as 10 percent of the Jewish communities in which the siblings lived, and sheds new light on the fluidity of race—as well as on the role of religion in racial shift—in the first half of the nineteenth century.