Paternal Genotype Research Articles

Optimizing purebred selection to improve crossbred performance.

Crossbreeding is a widely adopted practice in the livestock industry, leveraging the advantages of heterosis and breed complementarity. The prediction of Crossbred Performance (CP) often relies on Purebred Performance (PB) due to limited crossbred data availability. However, the effective selection of purebred parents for enhancing CP depends on non-additive genetic effects and environmental factors. These factors are encapsulated in the genetic correlation between crossbred and purebred populations ( ). In this study, a two-way crossbreeding simulation was employed to investigate various strategies for integrating data from purebred and crossbred populations. The goal was to identify optimal models that maximize CP across different levels of . Different scenarios involving the selection of genotyped individuals from purebred and crossbred populations were explored using ssGBLUP (single-step Genomic Best Linear Unbiased Prediction) and ssGBLUP-MF (ssGBLUP with metafounders) models. The findings revealed an increase in prediction accuracy across all scenarios as values increased. Notably, in the scenario incorporating genotypes from both purebred parent breeds and their crossbreds, both ssGBLUP and ssGBLUP-MF models exhibited nearly identical predictive accuracy. This scenario achieved maximum accuracy when was less than 0.5. However, at = 0.8, ssGBLUP, which exclusively included sire breed genotypes in the training set, achieved the highest overall prediction accuracy at 73.2%. In comparison, the BLUP-UPG (BLUP with unknown parent group) model demonstrated lower accuracy than ssGBLUP and ssGBLUP-MF across all levels. Although ssGBLUP and ssGBLUP-MF did not demonstrate a definitive trend in their respective scenarios, the prediction ability for CP increased when incorporating both crossbred and purebred population genotypes at lower levels of . Furthermore, when was high, utilizing paternal genotype for CP predictions emerged as the most effective strategy. Predicted dispersion remained relatively similar in all scenarios, indicating a slight underestimation of breeding values. Overall, the value emerged as a critical factor in predicting CP based on purebred data. However, the optimal model to maximize CP depends on the factors influencing . Consequently, ongoing research aims to develop models that optimize purebred selection, further enhancing CP.

Genomic characterisation and diversity assessment of eight endangered Belgian sheep breeds

Assessing the genetic diversity of local breeds is essential for conserving these unique breeds, which may possess unique traits. This study provides the genomic characterisation of eight indigenous sheep breeds in Belgium based on pedigree and single nucleotide polymorphism (SNP) analysis. A total of 687 sheep were genotyped and were subjected to a rigorous quality control, resulting in a set of 45 978 autosomal SNPs. Pedigree analysis showed breed-average inbreeding estimates between 3.3% and 11.3%. The genomic analysis included an assessment of runs of homozygosity (ROH) to examine the genomic inbreeding coefficient, with breed-average inbreeding coefficients estimated between 4.1% and 8.5%. Runs of homozygosity islands were identified in six of the eight breeds studied, with some exhibiting an incidence of up to 58%. Interestingly, several ROH islands overlapped with other breeds included in this study, as well as with international sheep breeds. Pedigree-based effective population sizes were estimated below 100 for all breeds, whereas genomic-based effective population sizes were below 24, indicating that these eight local sheep breeds are endangered. Principal component analysis, admixture analyses, and Fst computations were used to study the population structure and genetic differences. A neighbour−joining tree using 95 international sheep breeds positioned the eight local breeds in the group of milksheep, Texel sheep and the Scandinavian breeds. Additionally, the investigation of paternal oY1 genotypes revealed diverse lineage origins within the Belgian sheep population. This study refines and deepens our knowledge about the local sheep breeds in Belgium, thereby improving their management and conservation. Moreover, as these breeds are linked to other international breeds, these insights are significant for the global scientific community.

Positive Outcome in a Pregnancy with Anti-kell Alloimmunization Treated with Intravenous Immunglobulin and Therapeutic Plasma Exchange Despite Persistence of High Titre Antibody: A Case Report

Background: Few reports have been published about the current clinical management of anti-Kell alloimmunization in pregnancy; its low frequency of occurrence means that the few long series published have covered an extensive time period in which different treatment approaches have overlapped. The objective of the present paper is to present our experience in the clinical management of a pregnant woman who was positive for the anti-Kell antibody. Materials and Methods: The laboratory follow-up included the weekly measurement of the antibody titre, and identification of the paternal and fetal genotype. The clinical management included TPE and IVIG administration. Obstetric monitoring included ultrasonographic monitoring of the fetus. Case Description: We report a case of anti-Kell alloimmunization with high antibody titre at first observation. Testing for fetal DNA circulating in maternal blood confirmed positivity for KEL1 gene. The patient underwent fifteen sessions of TPE after 18 weeks of gestational age, followed by weekly IVIG infusion, which continued until 27 weeks of pregnancy. Anti-Kell titres were measured before and after each TPE session. The patient had no need for IUBT and delivered by cesarean section at 34 weeks of gestational age. Pregnancy resulted in a live birth with mild HDFN. Discussion: HDFN is a potentially lethal complication of alloimmunization, and IUBT is the standard treatment for severe fetal anemia. TPE and IVIG are two alternative treatment modalities described in the literature to avoid or postpone the need for IUBT transfusion. In the case reported, despite any substantial change in antibody titre, pregnancy resulted in a live birth. This result suggests that the use of TPE and IVIG in alloimmunization during pregnancy could be an effective treatment strategy.

Abstract A061: Grb7 is dispensible for normal development and ERBB2-driven mammary tumorigenesis, but maternal Grb7 deletion causes lactational insufficiency

Abstract Growth factor receptor-bound 7 (Grb7) is an adaptor protein implicated in signal transduction downstream of multiple receptor tyrosine kinases, including ERBB, FGFR and PDGFR pathways. Experimental studies have implicated Grb7 in regulating cell proliferation, survival, migration, and invasion through its large repertoire of protein-protein interactions. Here, we describe the generation and characterization of a Grb7 knockout (KO) mouse. These mice are viable and fertile. A lacZ knock-in reporter was used to visualize Grb7 promoter activity patterns in adult tissues, indicating widespread Grb7 expression in glandular epithelium, the central nervous system and other tissues. The sole defect observed in these animals was a failure of Grb7 KO females to successfully raise pups to weaning age, a phenotype that was independent of both paternal and pup genotypes. These data suggest a regulatory role for Grb7 in mammary lactational physiology. Grb7 is genomically adjacent to ERBB2 and commonly co-amplified with ERBB2 in human breast cancer. This adaptor protein physically interacts with ERBB2 and has been implicated in oncogenic signal propagation to intracellular pathways. We intercrossed Grb7 KO and MMTV-Neu mice to determine whether Grb7 is required for ERBB2-driven tumorigenesis. Surprisingly, there was no difference in time to tumor detection between cohorts, indicating that Grb7 is not obligately required for ERBB2-driven tumorigenesis. In conclusion, despite a considerable body of literature suggesting key roles for Grb7 in signal transduction pathways involved in both normal and malignant processes, our analysis of Grb7 KO mice demonstrates that Grb7 is largely dispensable for both development and ERBB2-driven tumorigenesis. These data raise the possibility that other Grb family members, Grb10 and Grb14, might compensate for Grb7 loss. Accordingly, a comprehensive assessment of all Grb family members may be needed to fully clarify their physiological roles. Citation Format: Kristopher A. Lofgren, Peter Feiszt, Paraic A. Kenny. Grb7 is dispensible for normal development and ERBB2-driven mammary tumorigenesis, but maternal Grb7 deletion causes lactational insufficiency [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr A061.

Offspring's own serotonin transporter genotype, independently from the maternal one, increases anxiety- and depression-like behavior and alters neuroplasticity markers in rats

IntroductionDevelopmental changes due to early life variations in the serotonin system affect stress-related behavior and neuroplasticity in adulthood. These outcomes can be caused both by offspring's own and maternal serotonergic genotype. We aimed to dissociate the contribution of the own genotype from the influences of mother genotype. MethodsSixty-six male homozygous (5-HTT−/−) and heterozygous (5-HTT+/−) serotonin transporter knockout and wild-type rats from constant 5-HTT genotype mothers crossed with varying 5-HTT genotype fathers were subjected to tests assessing anxiety- and depression-like behaviors. Additionally, we measured plasma corticosterone levels and mRNA levels of BDNF, GABA system and HPA-axis components in the prelimbic and infralimbic cortex. Finally, we assessed the effect of paternal 5-HTT genotype on these measurements in 5-HTT+/− offspring receiving their knockout allele from their mother or father. Results5-HTT−/− offspring exhibited increased anxiety- and depression-like behavior in the elevated plus maze and sucrose preference test. Furthermore, Bdnf isoform VI expression was reduced in the prelimbic cortex. Bdnf isoform IV and GABA related gene expression was also altered but did not survive false discovery rate (FDR) correction. Finally, 5-HTT+/− offspring from 5-HTT−/− fathers displayed higher levels of anxiety- and depression-like behavior and changes in GABA, BDNF and HPA-axis related gene expression not surviving FDR correction. LimitationsOnly male offspring was tested. ConclusionsOffspring's own 5-HTT genotype influences stress-related behaviors and Bdnf isoform VI expression, independently of maternal 5-HTT genotype. Paternal 5-HTT genotype separately influenced these outcomes. These findings advance our understanding of the 5-HTT genotype dependent susceptibility to stress-related disorders.

Grb7 knockout mice develop normally but litters born to knockout females fail to thrive.

Growth factor receptor-bound 7 (Grb7) is an adaptor protein involved in signal transduction downstream of multiple receptor tyrosine kinases, including ERBB, FGFR, and PDGFR pathways. Experimental studies have implicated Grb7 in regulating cell proliferation, survival, migration, and invasion through its large repertoire of protein-protein interactions. Here, we describe the generation and characterization of a Grb7 knockout mouse. These mice are viable and fertile. A lacZ knock-in reporter was used to visualize Grb7 promoter activity patterns in adult tissues, indicating widespread Grb7 expression in glandular epithelium, the central nervous system, and other tissues. The sole defect observed in these animals was a failure of Grb7 knockout females to successfully raise pups to weaning age, a phenotype that was independent of both paternal and pup genotypes. These data suggest a regulatory role for Grb7 in mammary lactational physiology.

Effects of parental genotypes on embryo rescue of seedless grape hybrid

ABSTRACT The success of seedless grape embryo rescue depends on many factors. To study the effects of parental genotypes on embryo rescue, we conducted 11 hybridisation combinations using nine stenospermocarpic seedless grapes as female parents and three seedless or seeded grapes as male parents. At the optimal sampling time of each mother plant, the hybrid ovules were inoculated and cultured on a solid–liquid biphasic MM3 medium. Then, the bare embryos were removed and inoculated on a WPM medium for germination and seedling formation. The results showed that when ‘Jupiter’ (seedless) was the male parent, ‘Perlette’ had the highest rates of embryo development, germination and seedling formation, followed by ‘Kunxiang Seedless’; when ‘Su-67’ (seedless) was the male parent, ‘FZ42’ had the highest embryo development rate; when ‘Beichun’ (seeded) was the male parent, ‘Fresno Seedless’ had the best embryo rescue results, followed by ‘Qinhong No.10’. These suggest that ‘Perlette’, ‘Kunxiang Seedless’, ‘Fresno Seedless’ and ‘Qinhong No.10’ are suitable female parents for embryo rescue. When ‘FZ42’ was the female parent, ‘Su-67’ was better than ‘Jupiter’ as the male parent; when ‘Perlette’ was the female parent, ‘Jupiter’ and ‘Su-67’ as male parents had no significant difference, indicating that paternal genotype has a certain effect on embryo rescue. HIGHLIGHTS The maternal genotype has a significant effect on the embryo rescue of seedless grapes. The paternal genotype has a certain effect on embryo rescue of seedless grapes. ‘Perlette’, ‘Kunxiang Seedless’, ‘Fresno Seedless’ and ‘Qinhong No.10’ are suitable female parents. A total of 345 hybrids from 11 cross-combinations were obtained by embryo rescue.

Familial 5.29 Mb deletion in chromosome Xq22.1–q22.3 with a normal phenotype: a rare pedigree and literature review

BackgroundXq22.1–q22.3 deletion is a rare chromosome aberration. The purpose of this study was to identify the correlation between the phenotype and genotype of chromosome Xq22.1–q22.3 deletions.MethodsChromosome aberrations were identified by copy number variation sequencing (CNV-seq) technology and karyotype analysis. Furthermore, we reviewed patients with Xq22.1–q22.3 deletions or a deletion partially overlapping this region to highlight the rare condition and analyse the genotype–phenotype correlations.ResultsWe described a female foetus who is the “proband” of a Chinese pedigree and carries a heterozygous 5.29 Mb deletion (GRCh37: chrX: 100,460,000–105,740,000) in chromosome Xq22.1–q22.3, which may affect 98 genes from DRP2 to NAP1L4P2. This deletion encompasses 7 known morbid genes: TIMM8A, BTK, GLA, HNRNPH2, GPRASP2, PLP1, and SERPINA7. In addition, the parents have a normal phenotype and are of normal intelligence. The paternal genotype is normal. The mother carries the same deletion in the X chromosome. These results indicate that the foetus inherited this CNV from her mother. Moreover, two more healthy female family members were identified to carry the same CNV deletion through pedigree analysis according to the next-generation sequencing (NGS) results. To our knowledge, this family is the first pedigree to have the largest reported deletion of Xq22.1–q22.3 but to have a normal phenotype with normal intelligence.ConclusionsOur findings further improve the understanding of the genotype–phenotype correlations of chromosome Xq22.1–q22.3 deletions.This report may provide novel information for prenatal diagnosis and genetic counselling for patients who carry similar chromosome abnormalities.

Non-random mating within an Island rookery of Hawaiian hawksbill turtles: demographic discontinuity at a small coastline scale.

Hawksbill sea turtles (Eretmochelys imbricata) from the Hawaiian archipelago form a small and genetically isolated population, consisting of only a few tens of individuals breeding annually. Most females nest on the island of Hawai'i, but little is known about the demographics of this rookery. This study used genetic relatedness, inferred from 135 microhaplotype markers, to determine breeding sex-ratios, estimate female nesting frequency and assess relationships between individuals nesting on different beaches. Samples were collected during the 2017 nesting season and final data included 13 nesting females and 1002 unhatched embryos, salvaged from 41 nests, of which 13 had no observed mother. Results show that most females used a single nesting beach laying 1-5 nests each. From female and offspring alleles, the paternal genotypes of 12 breeding males were reconstructed and many showed high relatedness to their mates. Pairwise relatedness of offspring revealed one instance of polygyny but otherwise suggested a 1 : 1 breeding-sex ratio. Relatedness analysis and spatial-autocorrelation of genotypes indicate that turtles from different nesting areas do not regularly interbreed, suggesting that strong natal homing tendencies in both sexes result in non-random mating across the study area. Complexes of nearby nesting beaches also showed unique patterns of inbreeding across loci, further indicating that Hawaiian hawksbill turtles have demographically discontinuous nesting populations separated by only tens of km.

ROOT SYSTEM ARCHITECTURE AND STEM TRAITS OF BREAD WHEAT SEEDLINGS UNDER CONTRASTING WATER REGIMES

Differential response of bread wheat seedlings to contrasting water regimes can be used to determine traits related to drought tolerance. The F1 offspring from eight crosses and 11 selected parental genotypes were simultaneously grown in hydroponic cultivation-polyethylene glycol (PEG) induced drought stress vs. control conditions. Criteria for selection of maternal and paternal genotypes were desirable traits in terms of increased tolerance to drought: longer stem length, longer primary root, large number of seminal roots, large root dry mass and stem dry mass, beginning of root branching at the greatest possible distance from beginning of the root, contrasting angle of seminal roots. The traits were measured on 14 day old seedlings: primary root length (PRL), distance to the first branch on the primary root (DFBR), number of seminal roots (NSR), total seminal root length (TSRL), angle of seminal roots (ASR), stem length (SL), root dry mass (RDM), stem dry mass (SDM), and the ratio of root dry mass to stem dry mass (RDM/SDM). Drought stress led to a decrease in the mean values of all root and stem traits by 11% on average, except for RDM/SDM which was increased. The most sensitive trait to drought stress was DFBR (25% reduction), causing root systems to branch at a shallower depth. In conditions of induced drought stress, the strongest statistically significant correlation was found among RDM and RDM/SDM (r = 0.794), SL and ASR (r = 0.708), RDM and TSRL (r = 0.673). The stress tolerance index had the strongest positive correlation with the SDM, PRL, TSRL, SL, and the stress susceptibility index with the NSR. The highest heterosis mean value was observed for PRL (24.6%) and for SL (15.6%) under drought stress. The different directions of average heterosis in induced drought stress vs. control conditions were observed for DFBR, RDM, and SDM, indicating differential traits to account for when planning breeding bread wheat for drought tolerance. Selected traits as criteria for selection and favorable combinations can be incorporated into pre-breeding and breeding schemes, directly or indirectly, aiming to achieve drought tolerance. Keywords: bread wheat; drought stress; heterosis; hydroponics; root system architecture.

The effects of pollen source on the fatty acid profile of Macadamia kernels

Macadamia nuts are an abundant source of the monounsaturated fats (59 %), oleic (50 %−65 %) and palmitoleic acid (12 %−30 %). As macadamia is generally an outcrossing species, this study focuses on the effect of both the maternal (seed parent) and paternal (pollen parent) genotype on the accumulation of the principal fatty acids in macadamia using a controlled 3 × 3 pollination trial. Both the seed parent and pollen parent were observed to significantly impact the fatty acid profile of macadamia nut kernels. In addition, the general combining abilities (GCA) of the parental cultivars and specific combining abilities (SCA) of parental crosses were determined, as well as identifying maternal/paternal combinations that could significantly increase palmitoleic acid and oleic acid, or decrease saturated fat concentration. These results provide evidence for the first time that pollen source has a significant impact on the fatty acid profile of macadamia kernels, and that previous reporting of the fatty acid profiles of macadamia cultivars is likely to be variable, due to the unknown genotype of pollen sources.

Examination of Nesting Behavior of Laying Hens of Different Genotypes Housed in Indoor Alternative Pens Using a Video System

The aim of the research was to examine how the nest selection preference of laying hens with different genotypes differed, the proportion of eggs laid in the litter, eggs laid in the upper and bottom nests, and the number and duration of nest visits. The experiment was conducted with laying hen genotypes provided by Bábolna TETRA Ltd. (Babolna, Hungary) (Commercial hybrid (C); pure-line maternal (Maternal); pure-line paternal offspring group (Paternal)). N = 318; n = 106 hen/genotype; and 53 hens/pen. We placed 53 19-week-old, non-beak-trimmed hens in each of the six 5.52 m2 alternative pens. We provided 14 nests for the hens at two levels per pen (3.8 hens/nest). We recorded the number of eggs laid in the nests on the bottom and upper levels, as well as within the litter. Infrared cameras were installed above the pens, and we conducted recordings on a test day at the beginning of the third production month. In our results, we found a significant difference in the proportion of litter eggs overall during the 12 months of production (C. hybrid: 30.7%; Paternal: 41.1%; Maternal: 10.2%). A significant difference was found between all genotypes in the proportions of eggs laid at the bottom (B) and upper (U) level during the 12 months of production (C. hybrid: B: 72.2%, U: 27.8%; Paternal: B: 88.0%, U: 12.0%; Maternal: B: 71.4%, U: 28.6%). The evaluation of the video recordings revealed that the C. hybrid and Paternal genotypes visited the bottom nests in 97.2% and 96.0% of the cases, respectively, and the Maternal genotype individuals in a significantly lower proportion, 72.5% of the cases; the Paternal genotype spent significantly more time (13.4 min) on average in the bottom nests compared with the C. hybrid (7.9 min) and the Maternal genotypes (8.6 min). Our conclusion is that it is not enough to ensure the desired ratio of egg nests in egg production, as laying hens may not use nests in certain positions at all. This generates a relative shortage of egg nests and can increase the ratio of eggs laid in the litter, which in turn involves human health risks.

QTL Mapping for Resistance to Bacterial Wilt Caused by Two Isolates of Ralstonia solanacearum in Chili Pepper (Capsicum annuum L.).

Bacterial wilt caused by the β-proteobacterium Ralstonia solanacearum is one of the most destructive soil-borne pathogens in peppers (Capsicum annuum L.) worldwide. Cultivated pepper fields in Korea face a continuous spread of this pathogen due to global warming. The most efficient and sustainable strategy for controlling bacterial wilt is to develop resistant pepper varieties. Resistance, which is quantitatively inherited, occurs differentially depending on R. solanacearum isolates. Therefore, in this study, we aimed to identify resistance quantitative trait loci (QTLs) in two F2 populations derived from self-pollination of a highly resistant pepper cultivar ‘Konesian hot’ using a moderately pathogenic ‘HS’ isolate and a highly pathogenic ‘HWA’ isolate of R. solanacearum for inoculation, via genotyping-by-sequencing analysis. QTL analysis revealed five QTLs, Bwr6w-7.2, Bwr6w-8.1, Bwr6w-9.1, Bwr6w-9.2, and Bwr6w-10.1, conferring resistance to the ‘HS’ isolate with R2 values of 13.05, 12.67, 15.07, 10.46, and 9.69%, respectively, and three QTLs, Bwr6w-5.1, Bwr6w-6.1, and Bwr6w-7.1, resistant to the ‘HWA’ isolate with phenotypic variances of 19.67, 16.50, and 12.56%, respectively. Additionally, six high-resolution melting (HRM) markers closely linked to the QTLs were developed. In all the markers, the mean disease index of the paternal genotype was significantly lower than that of the maternal genotype. The QTLs and HRM markers are expected to be useful for the development of pepper varieties with high resistance to bacterial wilt.

Influence of Pollen Dispersal and Mating Pattern in Domestication of Intermediate Wheatgrass, a Novel Perennial Food Crop.

Intermediate wheatgrass (IWG) is a perennial forage grass that is currently being domesticated as a grain crop. It is a primarily wind-pollinated outcrossing species and expresses severe inbreeding depression when self-pollinated. Characterization of pollen dispersal, mating parameters, and change in genetic diversity due to pollen movement is currently lacking in IWG. In this study, we examined pollen dispersal in an IWG selection nursery by evaluating 846 progeny from 15 mother plants and traced their parentage to 374 fathers. A set of 2,500 genomic loci was used to characterize the population. We assigned paternity to 769 (91%) progeny and the average number of fathers per mother plant was 37, from an average of 56 progeny examined per mother. An extensive number (80%) of pollination events occurred within 10 m of the mother plants. Pollination success was not correlated with trait attributes of the paternal genotypes. Mating system analysis confirmed that IWG is highly outcrossing and inbreeding was virtually absent. Neither genetic diversity nor the genome-estimated trait values of progeny were significantly affected by pollinator distance. The distance of pollinator in an IWG breeding nursery therefore was not found to be a major contributor in maintaining genetic diversity. These findings reveal the pollen dispersal model in IWG for the first time and its effect on genetic diversity, which will be valuable in designing future IWG breeding populations. Information generated and discussed in this study could be applied in understanding gene flow and genetic diversity of other open-pollinated species.

Using of Microsatellites to Study the Genetic Polymorphisms of SRYm18 Region in Iraqi Sheep

The origin of animals is usually determined by their paternal genotypes of the genes on the Y chromosome. In addition to the genes and their polymorphisms in the genome of mitochondria that are inherited through dams. In view of the lack of studies focusing on the genes of the Y chromosome in the world and their absence in Iraq. The aim of the present study was to identify the multiple genetic polymorphisms of the SRYM18 gene in the Arabi and Awassi sheep raised in Iraq. The study was conducted in the Genetic Engineering Laboratories - College of Agriculture, University of Basra, as well as in the Basra Genome Laboratory. The amplification of the SRYM18 gene showed genetic polymorphisms and gave a gene segment of (103-880) bp. The number of alleles of the SRYm18 gene was 13 alleles in the Arabi and 16 alleles in the Awassi breeds. The equilibrium test showed that the two breeds were under equilibrium. The two breeds were identical with nine alleles, while the number of special alleles for the Arabi breed was two, while the Awassi breed was distinguished by five. The number of rare alleles reached 20, of which seven were of the Arabi breed, and 13 of them were of the Awassi breed. Mean expected heterozygosity was 0.6386 with nonsignificant Fis for Arabi breed (0.1541) but significant for Awassi breed (0.2213). Mean neutrality was close to lower bound (0.1721) and (0.1270) for Arabi and Awassi breeds respectively

Mating System Analysis of <i>Acacia auriculiformis</i> in First and Second Generation Orchard Populations

Acacia auriculiformis A.Cunn.ex Benth is one of the fast growing exotic timber species. Thorough understanding of mating systems is influencing towards an efficient tree breeding design. Thus plant mating systems play an important role in shaping the genetic composition of progeny generations. Institute of Forest Genetics & Tree Breeding (IFGTB), Coimbatore has established Seedling Seed Orchards of Acacia auriculiformis in Southern States (Tamil Nadu and Kerala) of India. Two successive generations of this species were studied for its mating system based on microsatellite markers. Five microsatellite loci were studied among the three hundred half-sib progenies of both first and second orchard populations. Out-crossing rate was estimated The range of the maternal, paternal genotypes among the individuals in the family was also studied in the orchards. The present study indicated high out-crossing rate in first and second generation orchards population and it reflects that this species is highly out-crossed. The gene frequency estimates of the first and second generation progenies were studied that there was no significant variation in the pollen and ovule gene frequency estimate in both generations. The range of the maternal genotypes was 1 to 2 among the individuals in the family. The high out-crossing rate (tm=0.98; SE= 0.05; tm=1.0; SE=0.02) in the orchards indicated that the species is predominantly out-crossed.

MAGRARIO: UN NUEVO GENOTIPO PARA PRODUCIR CARNE OVINA DE CALIDAD

Generally there is poor tradition to produce and to commercialize heavy lean lamb carcasses. To achieve a better product for the ovine meat market Ideal (Polwarth) breed ewes were backcrossed to Texel breed rams (breed recognized to reduce carcass fat). Ideal breed (I) is one of the most ordinary breeds in Argentina. However, when their lambs are reared in feed-lot conditions, a high fat content is found in their lamb carcasses. After three generations of backcrosses followed by a breeding program for increase male lamb weaning weight and female fertility a new genotype was obtained for the local ovine meat production systems. This new genotype registered as Magrario (M) was obtained at Villarino Field Station of UNR (Zavalla, Santa Fe, 33º S, 61º W). It was verify that M produced more lean meat than I breed under feet lot conditions. M rams were introduced in flocks of Hampshire Down (HD) breed to evaluate lamb crosses with lean meat. Genotype M was compared under feed lot conditions with HD lambs during two months in the post weaning. Also crosses (MxHD), (MxI) and (IxHD) were evaluated in the same conditions. At the end of the experiment ultrasonic methods were used to evaluate fat depot on Longissimus dorsi. The (MxHD) showed a reduction of 20% respecting to HD. These results suggested that M genotype could be a useful paternal genotype to reduce fat depots when the aim is to produce lamb crosses under feed lot conditions in a short period of time. Key words: ovine, lean meat, feed lot, crossing.

Introgressions of Vitis rotundifolia Michx. to obtain grapevine genotypes with complex resistance to biotic and abiotic stresses.

Vitis rotundifolia Michx. is one of the species of the family Vitaceae, with resistance to both biotic and abiotic stresses. The present study reports new scientif ic knowledge about the inheritance of resistance to downy mildew, powdery mildew and frost by V. vinifera varieties from V. rotundifolia. Recombinant lines of three hybrid populations from the crossing of the maternal genotype ♀M. 31-77-10 with V. rotundifolia hybrids were used as the object of the study. As a result of laboratory screening, more than 40 % of recombinants of the ♀M. 31-77-10 × × [DRX-M5-734 + DRX-M5-753 + DRX-M5-790] population showed a high degree of frost resistance (–24 °C), while 6 % of transgressive recombinants were characterized by a very high degree of resistance (–27 °С). The maternal genotype ♀M. 31-77-10 does not carry alleles of resistance to powdery mildew at the Run1 locus and in the f ield suffers from powdery mildew much more than the paternal genotypes. The prevalence of powdery mildew on vegetative organs in the three recombinant populations over the years varies on average between 3.2–17.1, 0.3–17.7 and 0.6–5.2 %, respectively. As a result, almost all recombinant genotypes that received a resistant allele from the paternal genome are highly resistant to powdery mildew.

Cardiac and respiratory metabolic analysis of low-temperature tolerance in two geographic genotypes of Haliotis diversicolor and the hybrid

Evident survival heterosis exists in the hybrid (HdDY) of two Haliotis diversicolor geographic genotypes (maternal genotype HdTW and paternal genotype HdJP). To explore the physiological basis underlying the heterosis, we compared the survival rate, cardiac performance, oxygen consumption rate, and ammonia excretion rate of the three H. diversicolor genotypes at the low temperature. After one year of cultivation in the abalone farm, the survival rates of HdTW, HdJP, and HdDY were 27.76%, 86.90%, and 88.57%, respectively. The 50% lethal low temperature (LLT50) of HdTW was higher than HdJP and HdDY. During low-temperature exposure, the abalone’s heartbeat variation pattern appeared as three stages: the heartbeat decreasing stage, arrhythmia stage, and cardiac recovery stage. Four cardiac indices were developed to compare the three genotypes’ cardiac differences: the low-temperature heartbeat decreasing rate (LDR), cardiac arrhythmia temperature (CAT), low-temperature heartbeat recovering rate (LRR), and cardiac recovery time (CRT). HdTW had lower LDR and higher CAT than HdJP and HdDY, while HdJP had lower LRR and higher CRT than HdTW and HdDY, suggesting the hybrid’s cardiac function is parent-like in low-temperature tolerance and mother-like in low-temperature recovery. Meanwhile, the heart rates of HdJP and HdDY were always higher than HdTW at both normal temperature (20 °C) and low temperature (12 °C). The oxygen consumption rate and ammonia excretion rate of HdJP and HdDY were also higher than HdTW after low-temperature exposure. The results indicate the hybrid’s advantageous respiratory and metabolic functions at low temperatures, which could be a vital physiological mechanism of the hybrid’s survival heterosis. This study elucidates the cardiac and respiratory metabolic differences among different abalone genotypes at low temperatures, which may help us understand the physiological basis of mollusks’ low-temperature tolerance. The evaluation protocol and indices developed in this study could be helpful in mollusks’ physiological researches, such as the low-temperature tolerance heterosis, low-temperature adaption, and habitat differentiation.

Maternal and offspring genetic risk score analyses of fetal alcohol exposure and attention-deficit hyperactivity disorder risk in offspring.

BackgroundStudies investigating the effects of prenatal alcohol exposure on childhood attention‐deficit hyperactivity disorder (ADHD) symptoms using conventional observational designs have reported inconsistent findings, which may be affected by unmeasured confounding and maternal and fetal ability to metabolize alcohol. We used genetic variants from the alcohol metabolizing genes, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), as proxies for fetal alcohol exposure to investigate their association with risk of offspring ADHD symptoms around age 7–8 years.MethodsWe used data from 3 longitudinal pregnancy cohorts: Avon Longitudinal Study of Parents and Children (ALSPAC), Generation R study (GenR), and the Norwegian Mother, Father and Child Cohort study (MoBa). Genetic risk scores (GRS) for alcohol use and metabolism using 36 single nucleotide polymorphisms (SNPs) from ADH and ALDH genes were calculated for mothers (N ALSPAC = 8196; NMOBA = 13,614), fathers (N MOBA = 13,935), and offspring (N ALSPAC=8,237; N MOBA=14,112; N GENR=2,661). Associations between maternal GRS and offspring risk of ADHD symptoms were tested in the full sample to avoid collider bias. Offspring GRS analyses were stratified by maternal drinking status.ResultsThe pooled estimate in maternal GRS analyses adjusted for offspring GRS in ALSPAC and MoBa was OR = 0.99, 95%CI 0.97–1.02. The pooled estimate in offspring GRS analyses stratified by maternal drinking status across all the cohorts was as follows: ORDRINKING = 0.98, 95% CI 0.94–1.02; ORNO DRINKING = 0.99, 95% CI 0.97–1.02. These findings remained similar after accounting for maternal genotype data in ALSPAC and maternal and paternal genotype data in MoBa.ConclusionsWe did not find evidence for a causal effect of fetal alcohol exposure on risk of ADHD symptoms in offspring. The results may be affected by limited power to detect small effects and outcome assessment.