Paternal Line Research Articles

Pedigree-Based Description of Danubia Alba Rabbit Breed Lines.

The diversity of livestock animal breeds is an integral part of global biodiversity and requires careful management for sustainability and future availability. Avoiding inbreeding is a crucial aspect of mating of breeding animals. Our aims were to describe the quality of the pedigree, generation interval, gene origin, inbreeding, and effective population size of Danubia Alba rabbit lines. Line "D" is the maternal, whereas lines "C" and "X" are used as the paternal lines. The pedigree information was followed back from the actual breeding rabbits up to the founder animals. The rabbits having offspring in 2023 were chosen as reference populations for each line. The complete generation equivalent (GenCom) was 17.68 for line "C", 18.32 for line "D", and 17.49 for line "X", respectively. The maximum number of generations (GenMax) was above 30 for each line. The estimated bottleneck effect is mostly the result of selection and not a real genetic loss. The Wright inbreeding coefficient (F_Wright) was the highest for the "X" line rabbits, whereas it was the lowest for the line "D". Kalinowski's decomposition of inbreeding showed that it originated mostly from the past; the current fixation of alleles was quite similar for the line "C" and "D". Based on the predicted effective population sizes, it seems that there is no problem in maintaining of Danubia Alba lines.

Enhancing paternal rabbit line’s litter size through backcrossing strategy

After 39 generations of selection, a commercial paternal rabbit line, utilised by farmers through artificial inseminations with sperm from males in a three-way crossbreeding scheme based on average daily weight gain merit (ADG), present a deleterious effect on the reproductive performance. This poses a challenge for the continuation of the breeding program. To address this, our study employed repeated backcrossing, a strategy widely used in the recovery of endangered breeds, to improve the litter size traits of this paternal line. For this purpose, we used a maternal line characterised by its reproductive robustness merit (LP line). The study was conducted in two phases: initially, elite males from the R line were crossed with females from the LP line, and female offspring (BC1) were backcrossed twice with elite males from the R line to create the RLP population (BC3). The best sires and dams from the BC3 population were selected for breeding based on two phenotypically criteria: more than 50 g/day in ADG and being part of a litter with at least 7 live kits at weaning, over three generations. With this experimental design, the ADG merit of sires and dams in the G3 was more than 51 g/day. Regarding litter traits, significant improvements were observed due to heterosis, which diminished as the frequency of R line genes increased. Comparisons between BC1 and BC3 backcrosses showed 9.94 vs. 7.80 for litter size at birth (NB), 9.13 vs. 6.53 for number born alive (NBA), 7.19 vs. 4.99 for litter size at weaning (NW), and 5.65 vs. 4.54 for litter size at marketing (NM), respectively. Nevertheless, after three generations of selection (G3), the litter trait merit showed values of 7.46 for NB and 6.15 for NBA, with heritability of 0.12 and 0.11, respectively, resulting in an improvement of nearly 1 kit per parity (a 25% increase) compared to the R line. Our study illustrated the possibility of improving a rabbit paternal line in terms of litter size merit by integrating genes from a maternal line through three backcrosses, without compromising the ADG merit. This is crucial for extending our breeding program beyond the current 39 generations. HIGHLIGHTS Three backcrossing resulting in an improvement of nearly 1 kit per parity Backcrossing can enhance litter size merit without affecting growth rates. Progeny average daily gain merit remains stable across backcrossing efforts.

Novel Candidate Genes Involved in an Initial Stage of White Striping Development in Broiler Chickens.

White striping (WS) is a myopathy characterized by the appearance of white stripes parallel to the muscle fibers in the breast of broiler chickens, composed of adipose and connective tissues. This condition causes economic losses and, although common, its etiology remains poorly understood. Hence, the objective was to identify genes and biological mechanisms involved in the early stages of WS using a paternal broiler line that grows slightly slower than commercial ones, at 35 days of age, through the RNA sequencing of the pectoralis major muscle. Thirty genes were differentially expressed between normal and WS-affected chickens, with 23 upregulated and 7 downregulated in the affected broilers. Of these, 14 genes are novel candidates for WS and are implicated in biological processes related to muscle development (CEPBD, DUSP8, METTL21EP, NELL2, and UBE3D), lipid metabolism (PDK4, DDIT4, FKBP5, DGAT2, LIPG, TDH, and RGCC), and collagen (COL4A5 and COL4A6). Genes related to changes in muscle fiber type and the processes of apoptosis, autophagy, proliferation, and differentiation are possibly involved with the initial stage of WS development. In contrast, the genes linked to lipid metabolism and collagen may have their expression altered due to the progression of the myopathy.

Pear genomes display significant genetic diversity and provide novel insights into the fruit quality traits differentiation

The pear (Pyrus spp.) is well known for diverse flavors, textures, and global horticultural importance. However, the genetic diversity responsible for its extensive phenotypic variations remains largely unexplored. Here, we de novo assembled and annotated the genomes of the maternal (PsbM) and paternal (PsbF) lines of the hybrid ‘Yuluxiang’ pear and constructed the pear pangenome of 1.15 Gb by combining these two genomes with five previously published pear genomes representing cultivated and wild germplasm. Using the constructed pangenome, we identified 21 224 gene PAVs (Presence-absence variation) and 1 158 812 SNPs (Single Nucleotide Polymorphism) in the non-reference genome that were absent in the PsbM reference genome. Compared with SNP markers, PAV-based analysis provides additional insights into the pear population structure. In addition, some genes associated with pear fruit quality traits have differential occurrence frequencies and differential gene expression between Asian and European populations. Moreover, our analysis of the pear pangenome revealed a mutated SNP and an insertion in the promoter region of the gene PsbMGH3.1 potentially enhance sepal shedding in ‘Xuehuali’ which is vital for pear quality. PsbMGH3.1 may play a role in the IAA pathway, contributing to a distinct low-auxin phenotype observed in plants by heterologously overexpressing this gene. This research helps capture the genetic diversity of pear populations and provides genomic resources for accelerating breeding.

Rapid Mining of Candidate Genes for the Branchless Phenotype in Watermelon by Bulked Segregant Analysis Using Whole-genome Resequencing

Lateral branching is an important agronomic trait in horticulture plants. The aim of this project was to reveal the genetic mechanism, map the gene localization, and predict candidate genes of watermelon lateral branching. An F2 segregating population was derived from a cross between the multibranched maternal inbred line M6 and the branchless paternal inbred line N7. Two DNA pools were constructed using 20 multibranched plants and 20 branchless plants from the F2 population. Whole-genome resequencing was performed for the DNA pools (25×) and the parents (30×) to identify the genomic region associated with lateral branching. Candidate genes were predicted based on the gene annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analyses; then, quantitative validation of these genes was performed. The results showed that the clean reads of four samples yielded 64,295,076 to 81,658,958 bp, with sufficient genome coverage and high quality. Based on single-nucleotide polymorphism and insertions/deletions association analyses, the candidate genes were mapped to a 2.01-Mb region on chromosome 4 (22,958,925–24,971,894 bp) containing 182 annotated genes. During the KEGG and GO enrichment analyses, these genes were annotated to 10 cellular components, 10 molecular functions, and 12 biological processes. Eight candidate genes responsible for the branchless phenotype in watermelon were identified: Cla97C04G076340, Cla97C04G075820, Cla97C04G076060, Cla97C04G076250, Cla97C04G076280, Cla97C04G076380, Cla97C04G076830, and Cla97C04G075950. These genes were involved in amino acid biosynthesis and catabolism, TCP transcription factor activity, and regulation of flower development. This study offers valuable insights into the molecular mechanisms governing the branchless phenotype in watermelon. These candidate genes serve as potential targets for gene cloning and marker-assisted selection of watermelon cultivars without lateral branches.

Seed development-related genes contribute to high yield heterosis in integrated utilization of elite autotetraploid and neo-tetraploid rice.

Autotetraploid rice holds high resistance to abiotic stress and substantial promise for yield increase, but it could not be commercially used because of low fertility. Thus, our team developed neo-tetraploid rice with high fertility and hybrid vigor when crossed with indica autotetraploid rice. Despite these advances, the molecular mechanisms underlying this heterosis remain poorly understood. An elite indica autotetraploid rice line (HD11) was used to cross with neo-tetraploid rice, and 34 hybrids were obtained to evaluate agronomic traits related to yield. WE-CLSM, RNA-seq, and CRISPR/Cas9 were employed to observe endosperm structure and identify candidate genes from two represent hybrids. These hybrids showed high seed setting and an approximately 55% increase in 1000-grain weight, some of which achieved grain yields comparable to those of the diploid rice variety. The endosperm observations indicated that the starch grains in the hybrids were more compact than those in paternal lines. A total of 119 seed heterosis related genes (SHRGs) with different expressions were identified, which might contribute to high 1000-grain weight heterosis in neo-tetraploid hybrids. Among them, 12 genes had been found to regulate grain weight formation, including OsFl3, ONAC023, OsNAC024, ONAC025, ONAC026, RAG2, FLO4, FLO11, OsISA1, OsNF-YB1, NF-YC12, and OsYUC9. Haplotype analyses of these 12 genes revealed the various effects on grain weight among different haplotypes. The hybrids could polymerize more dominant haplotypes of above grain weight regulators than any homozygous cultivar. Moreover, two SHRGs (OsFl3 and SHRG2) mutants displayed a significant reduction in 1000-grain weight and an increase in grain chalkiness, indicating that OsFl3 and SHRG2 positively regulate grain weight. Our research has identified a valuable indica autotetraploid germplasm for generating strong yield heterosis in combination with neo-tetraploid lines and gaining molecular insights into the regulatory processes of heterosis in tetraploid rice.

Role of maternal-fetal immune tolerance in the establishment and maintenance of pregnancy.

Normal pregnancy is a contradictory and complicated physiological process. Although the fetus carries the human leukocyte antigen (HLA) inherited from the paternal line, it does not cause maternal immune rejection. As the only exception to immunological principles, maternal-fetal immune tolerance has been a reproductive immunology focus. In early pregnancy, fetal extravillous trophoblast cells (EVTs) invade decidual tissues and come into direct contact with maternal decidual immune cells (DICs) and decidual stromal cells (DSCs) to establish a sophisticated maternal-fetal crosstalk. This study reviews previous research results and focuses on the establishment and maintenance mechanism of maternal-fetal tolerance based on maternal-fetal crosstalk. Insights into maternal-fetal tolerance will not only improve understanding of normal pregnancy but will also contribute to novel therapeutic strategies for recurrent spontaneous abortion, pre-eclampsia, and premature birth.

Developmental origins of exceptional health and survival: A four-generation family cohort study.

Previous researched has demonstrated potent health and survival advantages across three-generations in longevity-enriched families. However, the survival advantage associated with familial longevity may manifest earlier in life than previously thought. We conducted a matched cohort study comparing early health trajectories in third-generation grandchildren (n = 5,637) and fourth-generation great-grandchildren (n = 14,908) of longevity-enriched sibships to demographically matched births (n = 41,090) in Denmark between 1973 and 2018. Lower risk was observed across a range of adverse early life outcomes in the grandchildren, including infant mortality (Hazard Ratio (HR) = 0.53, 95% CI [0.36, 0.77]), preterm birth (Odds Ratio (OR) = 0.82, [0.72, 0.93]), small for gestational age (OR = 0.83, [0.76, 0.90]) and neonatal respiratory disorders (OR = 0.77, [0.67, 0.88]). Relative advantages in parental education and maternal smoking were observed in both generations to a similar degree. However, a much smaller reduction in infant mortality was observed in the great-grandchildren (HR = 0.90, [0.70, 1.17]) and benefits across other outcomes were also less consistent, despite persisting socioeconomic and behavioural advantages. Lastly, maternal, and paternal lines of transmission were equipotent in the transmission of infant survival advantages. Descendants of longevity-enriched sibships exhibit a broad health advantage manifesting as early the perinatal period. However, this effect is strongly diluted over successive generations. Our findings suggest that exceptional health and survival may have early developmental components and implicate heritable genetic and or epigenetic factors in their specific transmission. Previous researched has demonstrated potent health and survival advantages across three-generations in longevity-enriched families. However, the survival advantage associated with familial longevity may manifest earlier in life than previously thought.In our study of third and fourth-generation descendants of longevity-enriched sibships, we observed a broad infant health and survival advantage reflected by protection against a diverse range of adverse birth outcomes.These advantages were strongly attenuated between the third and fourth generations, independent of otherwise stable socioeconomic and behavioural parental advantages, as well as maternal and paternal lines of transmission.Our findings suggest that familial aggregation of exceptional health and survival may have early life developmental components and triangulate to implicate heritable genetic and or epigenetic factors in their transmission.

The second life of the Rîșleacov mansion in Soldanesti

The Rîsleacov family was part of the category of Bessarabian nobles, Dvoreni of Ukrainian origin on the paternal line, ranked among the local nobility and recorded, in 1824, in the 3rd part of the Genealogical Book from Bessarabia. Both archival documents and oral history testify that the nobles of the Risleacov lineage contributed to the development of the locality, serving in state offices, being founders of the village church and local philanthropists. Being large landowners, the members of the Risleacov family built on their estate mills, a small brick factory, other small agrarian industrial units. The house and auxiliary constructions of the mansion, which initially covered an imposing area of 5 ha, have been preserved until now, and the documentary heritage with reference to this theme, offers the possibility of reconstructing the forgotten pages of the history of Bessarabia from the second half of the 19th century-20s of the 20th century. Currently, the Rîsleacov mansion is being brought back to life by the Soldanesti History and Ethnography Museum, finding its headquarters here which, unfortunately, is not included in the Register of state-protected monuments in the Republic of Moldova.

Влияние сублетальных доз хлорида кадмия на развитие доимплантационных зародышей в двух поколениях мышей

Cadmium is a heavy metal, highly toxic pollutant, entering the environment as a by-product of most modern industries. The effect of cadmium on the body depends on the route of entry, duration and dose of exposure. One of the important areas of this research is the study of the effect of cadmium on early development, leading to diseases in the adult body and possible developmental abnormalities in offspring. The aim of this study was to analyze the development of preimplantation embryos of mice exposed in utero to cadmium chloride and embryos obtained from cadmium-exposed parents. Preimplantation embryos of F1 (CBA×C57BL) hybrid mice exposed in utero to 30 µM of cadmium chloride (F1 — the first generation) and embryos of similar age, obtained from females and males, exposed in utero (F2 — the second generation), was studied. The toxic effect of cadmium chloride was studied by paternal, maternal and “double” (both parents were exposed) lines of inheritance. The development of embryos was assessed by the rate of blastomeres cleavage and the number of blastocysts. The F1 generation embryos exposed to cadmium chloride in utero passed the initial stages of cleavage and blastocyst formation faster compared to the control embryos. The development of the the maternal line second generation embryos (F2) was comparable with the control group. In the paternal and “double” (both parents were exposed) lines of inheritance, the rate of cleavage at the morula stage was slowdown, however, at the blastocyst stage, the rate of cleavage of embryos did not statistically differ from the control embryos. The effect of sublethal doses of cadmium chloride on famale mice at the onset of pregnancy affects not only the embryos of the first generation, directly exposed to cadmium chloride, but also the descendants of exposed parents in the second generation, slowing down the process of proliferation in the embryos of the paternal line of inheritance and in embryos born from two exposed parents. The results obtained in our model suggest that the harm from smoking caused by the accumulation of cadmium is manifested not only in children, but also in grandchildren. The epigenetic mechanism of such inheritance is most likely, which gives grounds for the development of preventive approaches to eliminate possible harmful consequences. It is advisable to recommend stopping smoking during pregnancy and in the period before conception.

Paternal starvation affects metabolic gene expression during zebrafish offspring development and lifelong fitness.

Dietary restriction in the form of fasting is a putative key to a healthier and longer life, but these benefits may come at a trade-off with reproductive fitness and may affect the following generation(s). The potential inter- and transgenerational effects of long-term fasting and starvation are particularly poorly understood in vertebrates when they originate from the paternal line. We utilised the externally fertilising zebrafish amenable to a split-egg clutch design to explore the male-specific effects of fasting/starvation on fertility and fitness of offspring independently of maternal contribution. Eighteen days of fasting resulted in reduced fertility in exposed males. While average offspring survival was not affected, we detected increased larval growth rate in F1 offspring from starved males and more malformed embryos at 24 h post-fertilisation in F2 offspring produced by F1 offspring from starved males. Comparing the transcriptomes of F1 embryos sired by starved and fed fathers revealed robust and reproducible increased expression of muscle composition genes but lower expression of lipid metabolism and lysosome genes in embryos from starved fathers. A large proportion of these genes showed enrichment in the yolk syncytial layer suggesting gene regulatory responses associated with metabolism of nutrients through paternal effects on extra-embryonic tissues which are loaded with maternal factors. We compared the embryo transcriptomes to published adult transcriptome datasets and found comparable repressive effects of starvation on metabolism-associated genes. These similarities suggest a physiologically relevant, directed and potentially adaptive response transmitted by the father, independently from the offspring's nutritional state, which was defined by the mother.

Construction of a Female Sterility Maintaining System Based on a Novel Mutation of the MEL2 Gene

BackgroundHybrid rice has significant yield advantage and stress tolerance compared with inbred rice. However, production of hybrid rice seeds requires extensive manual labors. Currently, hybrid rice seeds are produced by crosspollination of male sterile lines by fertile paternal lines. Because seeds from paternal lines can contaminate the hybrid seeds, mechanized production by mixed-seeding and mixed-harvesting is difficult. This problem can be solved if the paternal line is female sterile.ResultsHere we identified a female infertile mutant named h569 carrying a novel mutation (A1106G) in the MEL2 gene that was previously reported to regulate meiosis entry both in male and female organs. h569 mutant is female infertile but male normal, suggesting that MEL2 regulates meiosis entry in male and female organs through distinct pathways. The MEL2 gene and h569 mutant gave us tools to construct female sterility maintaining systems that can be used for propagation of female sterile lines. We connected the wild-type MEL2 gene with pollen-killer gene ZmAA1 and seed-marker gene DsRed2 in one T-DNA cassette and transformed it into ZZH1607, a widely used restorer line. Transgenic line carrying a single transgene inserted in an intergenic region was selected to cross with h569 mutant. F2 progeny carrying homozygous A1106G mutation and hemizygous transgene displayed 1:1 segregation of fertile and infertile pollen grains and 1:1 segregation of fluorescent and non-fluorescent seeds upon self-fertilization. All of the non-fluorescent seeds generated female infertile plants, while the fluorescent seeds generated fertile plants that reproduced in the way as their previous generation.ConclusionsThese results indicated that the female sterility maintaining system constructed in the study can be used to breed and propagate paternal lines that are female infertile. The application of this system will enable mechanized production of hybrid rice seed by using the mixed-seeding and mixed harvesting approach, which will significantly reduce the cost in hybrid rice seed production.

Parental preconception stress in zebrafish induces long-lasting anxiety in offspring

The growth and function of the vertebrate brain are impacted by environmental stimuli and early life stress. Adults who experience chronic stress during early life are more likely to suffer various neurodevelopmental and health issues. However, our understanding of how these specific environmental signals at different developmental stages affect brain development is poorly understood. In this study, we investigated if stress in parents prior to conception modulates neurodevelopment in offspring. We used a chronic unpredictable stress model adapted to zebrafish, which is an increasingly popular vertebrate model in neuroscience research to investigate the effects of both maternal and paternal preconception stress on offspring behavior. We evaluated the responsiveness of three anxiety-related behavioral paradigms in zebrafish: the novel tank test, thigmotaxis, and shoaling behavior. We found larvae from stressed females exhibited anxiety-like behavior in a thigmotaxis assay. As these larvae matured into adults, they continued to exhibit anxiety-like behavior in a novel tank and shoaling behavioral assay. These studies indicate preconception stress exposure in parents can induce life-long alterations in offspring neurodevelopment. Further, these results expand the hypothesis that chronically elevated glucocorticoid signaling not only in stressed mothers, but also stressed dads can affect neurodevelopment in offspring. We propose that zebrafish may be a useful model to study the transgenerational effects of chronic stress mediated via the maternal and paternal line.

Paternal intergenerational plasticity in the plant species Paeonia ostii: Implications for parental fitness and offspring performance

Abstract While there is long‐standing interest in the role of inter‐ and transgenerational plasticity via the maternal line, it rarely has been studied via the paternal line. Thus, consequences of the paternal environment for parental fitness and for performance of offspring in the environments experienced by either fathers or mothers are not known. We studied the intergenerational plasticity (IGP) of the plant species Paeonia ostii (Paeoniaceae) and tested the hypothesis that exposure of fathers to environmental stress (i) reduces parental fitness and performance of offspring grown under non‐stressful conditions, but (ii) mitigates the negative effects of environmental stress on fitness of parents and performance of offspring. Crosses were made in a greenhouse within six families of P. ostii between parents grown under drought and in a mesic environment, and the offspring of each cross were grown under both dry and mesic conditions. Production and germination of seeds and morphological and physiological traits of offspring were measured as indicators of parental fitness and offspring performance, respectively. Paternal drought decreased seed number per fruit, except when maternal plants also were grown in drought conditions. Offspring drought decreased seedling performance. However, when fathers experienced drought this negative effect on the offspring was partly mitigated, in particular when mothers also had experienced drought. In contrast, offspring grown in mesic conditions had improved seedling performance, especially when either parent (or both) also were grown in mesic conditions. Such statistical differences remained when seed mass was included as a covariate. Overall, paternal pollen of P. ostii mediated IGP to drought almost as well as it did for maternal ovules. IGP was adaptive if environments remained constantly dry across generations but maladaptive if environments changed. Hence, under future climate changes, paternal IGP might be both a blessing and a curse, with the blessing occurring when the focal habitat becomes drier and pollen comes from already‐dry places, while the curse may dominate in predictably moist habitats surrounded by drier habitats. Read the free Plain Language Summary for this article on the Journal blog.

Genetic basis of the phenomenon of male sterility and fertility restoration in maize (Zea mays L.) – a review

The phenomenon of male sterility in higher plants is, apart from protandry (earlier maturation of stamens), protogyny (earlier maturation of pistils), heterostyly (different stigmas) and self-incompatibility, one of the evolutionarily conditioned mechanisms forcing external pollination. Due to the elimination of the time- and cost-consuming emasculation of maternal lines, male-sterile lines are an object of interest in the seed production of hybrid cultivars of many plant species, including maize. Seed production of hybrid cultivars using male-sterile lines requires the establishment of maternal lines that are male-sterile in different environments and suitable paternal lines with fertility restorer genes. This paper summarizes the findings on the genetics of male sterility and fertility restoration in maize.

ВЛИЯНИЕ КРОССА РОДИТЕЛЬСКИХ ЛИНИЙ НА ВОСПРОИЗВОДИТЕЛЬНЫЕ И ПРОДУКТИВНЫЕ КАЧЕСТВА КОРОВ

The article presents the results of a comparative assessment of the reproductive and productive qualities of cows depending on the cross of parental lines in the conditions of Plemzavod "Urozhay" LLC, Ilishevsky district of the Republic of Bashkortostan. The research material was based on data from the Selex program. Dairy cattle" for the period from 2019 to 2023. The object of the study was the breeding stock of the herd belonging to the lines Vis Back Idial 1013415, Reflection Sovering 198998, Montvik Chieftain 95679 with a total number of 419 heads. It has been established that the highest milk productivity is ensured by a cross between the paternal line R. Sovering and the maternal line R. Sovering with a milk yield of 6599 kg. The most optimal service period is provided by the combination of the paternal line V.B. Aidial with the maternal line M. Chieftain, with a duration of 112.5 days. The highest value of the reproductive capacity coefficient was obtained by crossing the paternal line of M. Chieftain with the maternal line of M. Chieftain – 0.94

Study of Tomato Source Material for Breeding Highly Productive Hybrids

In world agriculture, the tomato plays a leading role due to its high nutritional properties, high yields, adaptive abilities and a wide range of uses in fresh, culinary and processing industries. The global tomato market volume is more than 160 million tons. In the ranking of countries, Russia is in 6th place in terms of area and 11th in terms of gross production of tomatoes. Unfortunately, at the moment, a significant part of tomato seed material is imported. The implementation of the import substitution program creates the need to develop domestic breeding and seed production of this crop. The purpose of these studies was to conduct a breeding assessment of parental tomato lines for productivity traits based on statistical analysis methods and to identify promising source material for further breeding work to develop highly productive hybrids. As a result of the research, three best combinations were identified in terms of productivity of hybrids: 2f2-16(8-2) x Veneta, 108t/20 x Victor and 2f216(8-2) x Victor, which have a positive effect of specific combining ability, have average and high positive effects of the general combining ability of both maternal and paternal lines. Two maternal lines 108t/20 and 3f-14 showed a positive general combining ability for early and total productivity and its components. therefore, these parents can be successfully used in future breeding programs.

Assessment of growth and development of hybrid duckling offspring

Currently, for agricultural enterprises of all ownership forms in the Republic of Kazakhstan, issues related to improving breeds, crosses, and lines of waterfowl remain important. Additionally, technologies for housing and feeding that enhance the survival and productivity of poultry are of great significance. The use of the genetic resources of domestic poultry breeds in breeding work, as well as the preservation of rare and endangered populations, holds special importance due to their high adaptive qualities in terms of both the quality and quantity of the obtained products, and their suitability for local feed and eco-climatic conditions. As a result of conducted research, an assessment of the quality of paternal and maternal lines of crosses from local duck populations in the Northern region of Kazakhstan has been performed, and indicators of growth, development, and survival of the obtained hybrid offspring have been studied. The conducted research has established that the "Ansar" crossbred ducklings exhibit higher growth energy along with a 94% survival rate of the offspring in early age.

Growth performance of three paternal rabbit lines with different potential for growth rate and resilience

This experiment aimed to compare the growth performance, digestive efficiency and health status of three paternal lines for growing rabbits. The R line was selected by growth rate during the growing period for 37 generations; the RF line was founded by selecting a population of elite R animals (average daily gain>60 g/d); and the RFLP line was founded by backcrossing males from the RF line with females from the LP maternal line. A total of 387 weaned rabbits were used to evaluate growing performance from weaning until 63 d of age in individual cages, in three batches. Additionally, 33 animals were used to determine nutrient digestive efficiency in a digestibility trial. Body weight and feed intake were controlled at weaning (28 d), 46 and 63 d of age. Mortality and morbidity were also monitored daily. During the digestibility trial, feed intake and faeces excretion were controlled daily. Results showed no significant effects of genetic type on body weight, daily feed intake and feed conversion ratio throughout the experiment. However, RF animals had a higher average daily gain from 28 to 46 d of age (+4.4%; P<0.05) compared with R animals, but lower from 46 to 63 d of age (–4.3%; P<0.05). Regarding digestive efficiency, RF and RFLP lines showed slightly higher faecal digestibility for dry matter and gross energy of the diet compared with the R line (+1.3 percentage points; P<0.05). Mortality was higher in animals from R and RF lines compared with RFLP (on av. 25.40 vs. 14.06%; P<0.05). Our results suggest that the introduction of resilient genetics could be a suitable strategy to improve the digestive health of paternal lines without affecting significantly their growth performance.

A New Inherited Syndrome Causing Sudden Cardiac Death with Distinct ST-Segment Depression and Ankyrin-2-Mutation.

Sudden cardiac death (SCD) is a serious threat. In individuals under the age of 35 years sudden arrhythmic death is the most frequent cause. In younger persons, genetically determined cardiac diseases (eg, cardiomyopathies and ion-channel diseases) account for an important proportion of these cases. We investigated the case of a 23-year-old male with SCD, specific ECG changes and left ventricular hypertrophy. Family history was significant for SCD in the paternal line. A precise analysis was performed by an international multidisciplinary expert panel including autopsy of the index patient's heart, molecular autopsy, whole-exome sequencing, analysis of the pedigree and examination of available family members. Three cases of SCD were reported in paternal relatives. The index patient exhibited specific ECG changes (ST-depression), which were also found in five paternal relatives and the brother of the index patient. Post-mortem analysis of the heart yielded mild idiopathic concentric hypertrophy without myocardial disarray. The genetic analysis of the index patient showed two nucleotide variations in two different genes (ANK2: c.11791G>A, MYO18B: c.3761G>A), which were also expressed in five relatives. Two family members had showed all indicators of the inherited syndrome including distinct ECG changes and genetic changes. We describe a distinct inheritable syndrome causing SCD, characterized by specific ECG changes and mutations of ANK2 and MYO18. As far as we know this is the first description of this syndrome.