Maternal Origin Research Articles

Genetic Origin and Introgression Pattern of Pingliang Red Cattle Revealed Using Genome-Wide SNP Analyses.

The Pingliang red cattle, an outstanding indigenous resource in China, possesses an exceptional breeding value attributed to its tender meat and superior marbling quality. Currently, research efforts have predominantly concentrated on exploring its maternal origin and conducting conventional phenotypic studies. However, there remains a lack of comprehensive understanding regarding its genetic basis. To address this gap, we conducted a thorough whole-genome analysis to investigate the population structure, phylogenetic relationships, and gene flows of this breed using genomic SNP chip data from 17 bovine breeds. The results demonstrate that Pingliang red cattle have evolved distinct genetic characteristics unique to this breed, clearly distinguishing it from other breeds. Based on the analysis of the population structure and phylogenetic tree, it can be classified as a hybrid lineage between Bos taurus and Bos indicus. Furthermore, Pingliang red cattle display a more prominent B. taurus pedigree in comparison with Jinnan, Qinchuan, Zaosheng, Nanyang, and Luxi cattle. Moreover, this study also revealed closer genetic proximity within the Chinese indigenous cattle breed, particularly Qinchuan cattle, which shares the longest identical by descent (IBD) fragment with Pingliang red cattle. Gene introgression analysis shows that Pingliang red cattle have undergone gene exchange with South Devon and Red Angus cattle from Europe. Admixture analysis revealed that the proportions of East Asian taurine and Chinese indicine in the ancestry of Pingliang red cattle are approximately 52.44% and 21.00%, respectively, while Eurasian taurine, European taurine, and Indian indicine account for approximately 17.55%, 7.27%, and 1.74%. Our findings unveil distinct genetic characteristics in Pingliang red cattle and attribute their origin to B. taurus and B. indicus ancestry, as well as contributions from Qinchuan cattle, South Devon, and Red Angus.

Clinical and Genetic Characteristics of 30 Patients Misdiagnosed As Having ITP with Non-Muscle Myosin Heavy Chain 9-Related Disease (MYH9-RD): A Retrospective Analysis in China

Introduction : Non-muscle myosin heavy chain 9-related diseases (MYH9-RD) are rare autosomal dominant platelet (PLT) disorders presenting as nonsyndromic forms characterized by macrothrombocytopenia with giant PLTs and leukocyte inclusion bodies or as syndromic forms combining these hematological features with deafness, nephropathy, or cataracts. Owing to its low incidence and similar clinical manifestations, it is easily misdiagnosed as immune thrombocytopenia (ITP), leading to inappropriate treatment. To improve the diagnosis of this rare thrombocytopenic disease and minimize the misdiagnosis rate, we retrospectively analyzed the clinical, treatment, and genetic characteristics of patients with MYH9-RD who were initially misdiagnosed with ITP and compared the differences between pediatric and adult patients. Methods: Patients from various sites in China were enrolled. The inclusion criteria were macrothrombocytopenia on peripheral blood smear, MYH9 gene mutation detected by next-generation sequencing or whole exon sequencing and verified by Sanger sequencing, and absence of other acquired thrombocytopenia diseases. We collected basic information, clinical manifestations, and laboratory test results via medical records and telephone interviews. Results: Of the 30 patients, 17 were male, 13 were female, 14 were children, and 16 were adults. There was no significant difference in the mean PLT count (×10 9/L) at the time of diagnosis between children and adults (50.5 vs. 33.4, P=0.188). However, the median duration of misdiagnosis was significantly shorter in children (0.1 y vs. 9 y, P=0.000) (Table 1). Overall, 5 patients showed no signs of bleeding, while 25 presented with bleeding manifestations: 11 with skin bleeding spots and ecchymosis, 15 with epistaxis, 6 with gingival bleeding, and 3 with increased menstrual volume. Moreover, 21 patients showed no non-hematological manifestations, while 9 presented with non-hematological manifestations, which occurred exclusively in adult patients. Among the latter, 6 patients had nephropathy (2 underwent renal transplantation, and 2 underwent regular dialysis), 5 had hearing impairment (4 underwent high-frequency hearing impairment, and 1 received a cochlear implant due to deafness), and 1 had a congenital cataract. All patients received first- or second-line treatment for ITP. The most common treatment in children was immunoglobulins (12/14), followed by steroids (5/14) and traditional Chinese medicine (2/14). No children received >3 types of treatment, 4 children received >1, and 6 adult patients received >3. The highest number of treatment type for a single patient was up to 7. The median duration of ITP treatment was 1.5 y for adults and 0.1 y for children ( P=0.002). All patients presented heterozygous missense mutations in MYH9; 17/30 were spontaneous mutations, 7/30 were familial mutations (involving 6 paternal and 1 maternal origin), and 6/30 cases had an unknown inherited type. Fourteen cases were located in the N-terminal globular head region, and 16 cases were located in the C-terminal tail domain (Figure 1). Two novel mutations (not recorded in the Global Variome database), p. G1517V and p. K1674Q, were identified. In 2 adult patients with p.R702C mutations, proteinuria occurred in adolescence, followed by chronic renal failure (CRF), end-stage renal failure, and hearing loss. The 3 children with p.R702C mutation were aged <4 years and exhibited no non-hematological symptoms. Three of the 5 adults with p.E1841K mutations had CRF and underwent kidney transplantation. Conclusion s : Compared with pediatric patients, adult patients are more likely to be misdiagnosed with ITP, receive more types of inappropriate treatment for a longer period of time, and have more common non-hematological manifestations. To improve diagnostic accuracy and reduce the misdiagnosis rate for patients with thrombocytopenia, especially those with a poor response to ITP treatments, attention should be paid to mean PLT volume, family history, and genetic screening. Consistent with previous reports, patients with the p.R702C mutation showed early-stage kidney injury and hearing loss. The incidence of spontaneous mutations (56.7%) was significantly higher than previously reported (25-35%). The genetic characteristics of MYH9-RD and genotype-phenotype relationships in China require further clarification.

Mitochondrial Diversity and Phylogenetic Relationship of Eight Native Bulgarian Sheep Breeds

The geographical, geomorphological, and climatic characteristics of Bulgaria are particularly favorable for animal breeding and, above all, for pastoral farming and sheep breeding. These conditions created prerequisites for the creation of about 30 unique local breeds of sheep. In this study we investigated the genetic diversity of eight of the most popular Bulgarian native breeds, based on the sequence analysis of a part of the mitochondrial D-loop region. An almost entire mitochondrial DNA (mtDNA) D-loop region (1180 bp) was amplified and sequenced. The obtained results showed the presence of a large number of haplotypes – 225, belonging to two main haplogroups. The majority of samples showed a high prevalence of the European haplogroup B (95.2%) while the remaining individuals were assigned to haplogroup A (4.8%). None of the other reported mitochondrial haplogroups were observed. The number of polymorphic sites, nucleotide and haplotype diversity was high (240, 0.01237, and 0.9968, respectively), which is evidence for multiple maternal origins in all populations. The Tajima D-test value in all the study populations was −1.905 (p < 0.05), indicating that the abundance of rare alleles was most likely due to population expansion after a recent bottleneck. The Median joining network showed that almost all haplotypes belonging to haplogroup B formed a star-like network, which revealed a weak genetic differentiation and a large gene flow between the Bulgarian native breeds.

Droplet Digital PCR for Fast and Accurate Characterization of NF1 Locus Deletions: Confirmation of the Predominant Maternal Origin of Type-1 Deletions

Neurofibromatosis type-1 is a genetic disorder caused by loss-of-function variants in the tumor-suppressor NF1. Approximately 4% to 11% of neurofibromatosis type-1 patients have a NF1 locus complete deletion resulting from nonallelic homologous recombination between low copy repeats. Codeleted genes probably account for the more severe phenotype observed in NF1-deleted patients. This genotype-phenotype correlation highlights the need for a detailed molecular description. A droplet digital PCR (ddPCR) setalong the NF1 locus was designed to delimitate the three recurrent NF1 deletion breakpoints. The ddPCR was tested in 121 samples from nonrelated NF1-deleted patients. Classification based on ddPCR versus multiplex ligation-dependent probe amplification (MLPA) was compared. In addition, microsatellites were analyzed to identify parental origin of deletions. ddPCR identified 77 type-1 (64%), 20 type-2 (16%), 7 type-3 (6%), and 17 atypical deletions (14%). The results were comparable with MLPA, except for three atypical deletions misclassified as type-2 using MLPA, for which the SUZ12 gene was not deleted. A significant maternal bias (25 of 30) in the origin of deletions was identified. This study proposes a fast and efficient ddPCR quantification to allow fine NF1 deletion classification. It indicates that ddPCR can be implemented easily into routine diagnosis to complement the techniques dedicated to NF1 point variant identification. This new tool may help unravel the genetic basis conditioning phenotypic variability in NF1-deleted patients and offer tailored genetic counseling.

Type II Abernethy malformation with cystic fibrosis in a 12-year-old girl: A case report

BACKGROUND Abernethy malformation, also known as congenital extrahepatic portosystemic shunt, is an uncommon malformation resulting from aberrant development of the portal venous system. Cystic fibrosis (CF) is an autosomal recessive genetic disease caused by mutations in the CFTR gene. It mainly affects the exocrine glands of the respiratory, digestive and reproductive systems. It is considered extremely rare in the Asian population. We present a clinical case involving a pediatric patient of Asian descent who was diagnosed with Abernethy malformation and CF. CASE SUMMARY A 12-year-old girl presented with a medical history of recurring respiratory infections and hemoptysis, and chest computed tomography (CT) showed bronchiectasis. Whole exome sequencing was performed for the patient, yielding findings that revealed a compound heterozygous variant of the CFTR gene: c.233_c.234insT/p.Trp79fsTer3 (maternal origin); c.2909G>A/p.Gly970Asp (paternal origin). CF was diagnosed. The physician’s attention was drawn to the presence of splenomegaly during disease progression. Abdominal enhanced CT revealed splenomegaly, compression of the left kidney, and multiple tortuous dilated vascular shadows were seen at the splenic hilum, which flowed back into the left renal vein and portal vein, suggesting Abernethy malformation type II. Intraoperatively, the abnormal blood flow was seen to merge into the inferior vena cava through the left renal vein without hepatic processing, and the pathology of liver biopsy showed hypoplastic, dilated or absent portal vein branches, both of which supported the diagnosis of Abernethy malformation type II. This represents the initial documented instance of Abernethy malformation accompanied by a CFTR gene mutation in the existing body of literature. CONCLUSION Coexisting Abernethy malformation and CF are rare. Detailed medical history information, abdominal enhanced CT, venography and genetic testing contribute to diagnosis as well as differential diagnosis.

Incidence and risk factors for umbilical cord prolapse in labor when amniotomy is used and with spontaneous rupture of membranes: A Swedish nationwide register study.

Umbilical cord prolapse (UCP) is a rare but severe obstetric complication in the presence of a rupture of the membranes. Although it is not possible to prevent a spontaneous rupture of the membranes (SROM), it is possible to prevent an amniotomy, which is a commonly used intervention in labor. This study aimed to explore the incidence and risk factors that are associated with UCP in labor when amniotomy is used vs SROM. A retrospective nationwide register study was conducted of all births in Sweden from January 2014 to June 2020 that were included in the Swedish Pregnancy Register (n = 717 336). The main outcome, UCP, was identified in the data by the International Classification of Diseases (ICD-10) diagnosis code O69.0. Multiple binary logistic regression analysis was used to identify the risk factors. Amniotomy was performed in 230 699 (43.6%) of all pregnancies. A UCP occurred in 293 (0.13%) of these cases. SROM occurred in 298 192 (56.4%) of all cases, of which 352 (0.12%) were complicated by UCP. Risk factors that increased the odds of UCP for both amniotomy and SROM were: higher parity, non-cephalic presentation and an induction of labor. Greater gestational age reduced the odds of UCP. Risk factors associated with only amniotomy were previous cesarean section and the presence of polyhydramnios. Identified risk factors for UCP in labor with SROM were a higher maternal age and maternal origin outside of the EU. UCP is a rare complication in Sweden. Beyond confirming the previously recognized risk factors, this study found induction of labor and previous cesarean section to be risk factors in labor when amniotomy is used.

279 Maternal Programming of the Piglet Microbiome Through Supplementation with a Yeast Feed Additive

Abstract The objective of this study was to investigate effects of live yeast supplementation of sow diets during late gestation and lactation on sow reproductive performance and piglet microbiome development. Three dietary treatments were imposed on mixed-parity sows (n = 92) from three contemporary farrowing groups during late gestation and lactation. Dietary treatments were based upon the inclusion level (%) of Actisaf Sc47 in corn/soybean meal-based diets: Control (C, 0%), Low (L, 0.1%), and High (H, 0.5%). Sows were fed their assigned gestation diet (1.8 kg ∙animal-1∙day-1/) from days 85 to 110 of gestation. On day 111 of gestation, sows were fed their assigned lactation diet (3.6 kg/head/day) until parturition. Sows were allowed ad libitum access to their assigned lactation diet beginning day one postpartum until piglets were weaned. Fecal and vaginal swabs were collected from all sows on day 85 of gestation (T1-S) and the day before parturition (T2-S). Colostrum and milk samples were collected from 30 focal sows (10/treatment group), and fecal swabs were collected from 6 piglets per focal sow (n = 180) at 24 to 36 hours after birth (T1-P) and weaning (T2-P, ~19 days old). Extracted DNA from swab samples was sequenced on the MiSeq platform targeting the V4 variable region of the 16S rRNA bacterial gene, and sequence data were analyzed using DADA2 plus various packages within the R statistical software. Generalized linear mixed models were built for sow performance data using the R lme4 package, with treatment as a fixed effect, and farrowing group, parity, and sire as random effects. Piglet performance models also included sex as a fixed effect and maternal origin instead of sire as a random effect. No significant differences were observed among dietary treatment groups for gestation or lactation length, lactation feed intake, sow body weights, sow backfat depth, litter size at birth or weaning, pre-weaning piglet mortalities, or piglet growth performance. Although alpha and beta diversity did not differ among maternal dietary treatment groups in sow colostrum, milk, fecal, or vaginal samples (T1-S or T2-S), several taxa were significantly enriched or less abundant in sow samples based upon dietary yeast inclusion levels. Diversity of piglet fecal microbiomes was not different across maternal dietary treatment groups, but community composition was different at both time-points (T1-P: PERMANOVA, R2 = 0.13, P=0.02; T2-P: PERMANOVA, R2 = 0.01, P=0.048). These results indicate that yeast supplementation in sow diets in late gestation and lactation may influence development and composition of piglet gut microbiomes in early life.

Genetic diversity and maternal origin of Vietnamese indigenous chicken breeds inferred from complete sequences of mitochondrial DNA D-loop region

Genetic diversity and maternal origin of Vietnamese indigenous chicken breeds inferred from complete sequences of mitochondrial DNA D-loop region

The maternal epigenome as a window into the in utero environment that the foetus experiences

Maternal stress pre-pregnancy and exposure to stress in utero has life-long negative consequences for the developing foetus. There is growing evidence that this passes through changes in foetal epigenetic markers such as DNA methylation. We hypothesize that the mother’s prior life experience and changes in her external environment will change the in utero environment she provides to the developing foetus, and both will be reflected in changes to the mother’s epigenome. As classical dogma states that during embryo all DNA methylation marks are removed and replaced de novo, this raises the question as to how to assess the in utero environment, examining the role it plays in the transmission of environmental cues. We suggest that the maternal epigenome can act as a proxy for the developmental environment she provided to her offspring in utero; this developmental environment determines the child’s epigenome and lifelong health trajectory. Furthermore, we suggest that the maternal origin of the placental decidua make this the perfect sample for assessing the in utero environment in the context of the mothers’ prior life experience, mediating maternal exposure to infant phenotype.

Comparative analysis of chloroplast genomes of two Chinese local citrus varieties and haplotype analysis with other citrus species

Citrus plants, comprising some of the most widely cultivated fruit crops worldwide, have great research value. We assembled and annotated the chloroplast genomes of two local important citrus varieties of China, ‘Tuju’ and ‘Zangju’, and comparatively analyzed their sequences. The full lengths chloroplast genomes of ‘Tuju’ and ‘Zangju’ were 160,121 and 160,694 bp, respectively. Both featured a quadripartite structure with two copies of a large inverted repeat (IR) separated by small (SSC) and large (LSC) single-copy regions. ‘Tuju’ chloroplast genome contained 134 genes. ‘Zangju’ had one less protein-coding gene (rpl22) than ‘Tuju’. We also found 27 and 21 optimal codons, all of which ended with A or U, for chloroplast protein-coding genes of ‘Tuju’ and ‘Zangju’, respectively. There were 32 haplotypes obtained from 43 citrus chloroplast genomes, some different species or cultivars could share one haplotype. Of them, ‘Tuju’, one individual of Citrus limon, one individual of Citrus maxima and Citrus platymamma shared one haplotype, which implied they had the same maternal origin. The phylogenetic trees supported that all haplotypes could be divided five groups, while haplotype network analysis tended to get three groups. Our study reveals the complex lineage relationship of citrus plants at a certain level, and provides a valuable reference tool for future research on citrus plants.

FRI375 Validation Of A Novel Mouse Placenta Explant Protocol For Screening Of Drugs Modulating Circadian Rhythms

Abstract Disclosure: J.S. Lee: None. H.M. Hoffmann: None. Introduction Pre-eclampsia is one of the leading causes of maternal, fetal, and neonatal morbidity and mortality, complicating about 4% of pregnancies. Recent work has identified PERIOD3 (PER3), a gene regulating 24-hour circadian rhythms, to be downregulated in the preeclamptic placenta. The role of circadian rhythms in the placenta largely remains unknown. Our goal is to establish an organotypic placental preparation to allow screening of drugs that regulate circadian rhythms. These studies are a first step towards understanding how circadian rhythm changes are caused in the placenta and will be the basis for future studies to understand how circadian rhythm disruption in the placenta cause pregnancy complications, such as preeclampsia. Methods We established a novel organotypic placenta preparation allowing to study circadian rhythms in a LumiCycle using gestation day (GD) 14 and GD18 placental explants from the validated circadian reporter mouse Per2::Luciferase. Using H&E we validated the explants to be >80% enriched in either decidua (DC) which is strictly of maternal origin, labyrinth (LB) which is strictly of fetal origin, and the junctional zone (JZ) which consists of binucleated cells fused of maternal and fetal cells. Results Through H&E staining, we validated by distinct morphology that the DC is enriched with neutrophils; the JZ contains spongiotrophoblasts and glycogen trophoblasts; whereas the LB has anucleated red blood cells. We next established a protocol to record Per2::Luciferase circadian rhythms for <6 days. We found that the Per2::Luciferase circadian rhythm shortens with increased gestational age, where the period in DC, LZ and LB in the GD14 placenta is ∼4h longer than in the GD18 placenta, showing an unexpected plasticity in circadian timekeeping in the placenta. Because PER3 is downregulated in the pre-eclamptic placenta, we asked if the explants would be useful for pharmacologically screenings. We applied PF670462 (1μM), which stabilizes PER1/2/3, or epidermal growth factor (EGF, 30ng/mL), a growth factor important in placental function and a PER2 enhancer. PF670462 lengthened Per2::Luciferase period in the DC and JZ, confirming the expected circadian rhythm stabilizing effect of PF670462. Surprisingly, EGF only modulated circadian rhythms in the GD14 placental, where EGF shortened Per2::Luciferase period in DC, and lengthen the period in the JZ and LB zones in the GD14 placenta. This data suggests EGF has gestational age and placenta zone specific effects. Conclusion We validated a novel ex vivo placental preparation to study circadian rhythms at GD14 and GD18. We identified a placenta zone and gestation age specific effect of EGF, an effect future studies will further expand on. This model will be useful to complete pharmacological screenings of drugs that can restore circadian rhythms in the preeclamptic placenta. Presentation: Friday, June 16, 2023

Uniparental disomy: expanding the clinical and molecular phenotypes of whole chromosomes.

Uniparental disomy (UPD) refers to as both homologous chromosomes inherited from only one parent without identical copies from the other parent. Studies on clinical phenotypes in UPDs are usually focused on the documented UPD 6, 7, 11, 14, 15, and 20, which directly lead to imprinting disorders. This study describes clinical phenotypes and genetic findings of three patients with UPD 2, 9, and 14, respectively. Chromosomal microarray (CMA), UPDtool, methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) and whole-exome sequencing (WES) analysis were performed to characterize the genetic etiology. The CMA revealed a homozygous region involving the whole chromosome 2 and 9, a partial region of homozygosity in chromosome 14. UPD-tool revealed a paternal origin of the UPD2. MS-MLPA showed hypomethylation of imprinting gene MEG3 from maternal origin in the UPD14 case. In addition, UPD14 case displayed complex symptoms including growth failure, hypotonia and acute respiratory distress syndrome (ARDS), accompanied by several gene mutations with heterozygous genotype by WES analysis. Furthermore, we reviewed the documented UPDs and summarized the clinical characteristics and prognosis. This study highlighted the importance to confirm the diagnosis and origin of UPD using genetic testing. Therefore, it is suggested that expanding of the detailed phenotypes and genotypes provide effective guidance for molecule testing and genetic counseling, and promote further biological investigation to the underlying mechanisms of imprinted disorders and accompanied copy number variations.

Identification of protein biomarkers associated with congenital diaphragmatic hernia in human amniotic fluid

Congenital diaphragmatic hernia (CDH) is a severe birth defect frequently associated with pulmonary hypoplasia, pulmonary hypertension, and heart failure. Since amniotic fluid comprises proteins of both fetal and maternal origin, its analysis could provide insights on mechanisms underlying CDH and provide biomarkers for early diagnosis, severity of pulmonary changes and treatment response. The study objective was to identify proteomic changes in amniotic fluid consistently associated with CDH. Amniotic fluid was obtained at term (37–39 weeks) from women with normal pregnancies (n = 5) or carrying fetuses with CDH (n = 5). After immuno-depletion of the highest abundance proteins, off-line fractionation and high-resolution tandem mass spectrometry were performed and quantitative differences between the proteomes of the groups were determined. Of 1036 proteins identified, 218 were differentially abundant. Bioinformatics analysis showed significant changes in GP6 signaling, in the MSP–RON signaling in macrophages pathway and in networks associated with cardiovascular system development and function, connective tissue disorders and dermatological conditions. Differences in selected proteins, namely pulmonary surfactant protein B, osteopontin, kallikrein 5 and galectin-3 were validated by orthogonal testing using ELISA in larger cohorts and showed statistically significant differences aiding in the diagnosis and prediction of CDH. The findings provide potential tools for clinical management of CDH.

Single hybrid population but multiple parental individuals at the origin of parthenogenetic rock lizards Darevskia sapphirina and D. bendimahiensis Schmidtler, & Eiselt Darevsky (1994) endemic to the area of Lake Van in East Turkey

Among vertebrates, obligate parthenogenesis is only found in Squamata, where it always has a hybrid origin and a few lizard genera contain most of the known hybridogenous parthenogenetic taxa. Parthenogenesis thus seems to be pre-conditioned at the genus level, but it is not clear how often the encounter between two parental sexually reproducing species can result in the parthenogenetic offspring, nor whether the success of such hybridization event requires certain conditions or the specific time frame. To address this question, we studied the rock lizards of genus Darevskia, where a pair of parental species, D. valentini and D. raddei, as well as their parthenogenetic daughter species D. bendimahiensis and D. sapphirina, are found in close proximity NE of the Lake Van in East Anatolia. Using ddRAD-seq genotyping on 19 parental and 18 hybrid individuals, we found that (i) all parthenogenetic individuals from both D. bendimahiensis and D. sapphirina have a monophyletic origin tracing back to a single initial hybrid population, but their current genetic variation is geographically structured; (ii) unlike the most probable paternal ancestor, the genetically closest extant population of the maternal ancestor is not the geographically nearest one; and (iii) in the parthenogens, about 1% of loci carry multiple haplotypes, frequently differentiated by multiple substitutions. This pattern, in addition to biases in the relative frequency of haplotypes of maternal and paternal origin, does not appear compatible with a scenario of the entire parthenogenic clonal population having descended from a single pair of parental individuals. Instead, the data suggest that multiple parental individual ancestries still persist in the parthenogenetic gene pool. This supports the notion that although hybridization leading to parthenogenesis is generally rare at the level of species, it may be more common at the individual/population level once the right conditions are met.

A de novo 2.3 kb structural variant in MITF explains a novel splashed white phenotype in a Thoroughbred family.

Splashed white in horses is characterized by extensive white patterning on the legs, face and abdomen and may be accompanied by deafness. To date, seven variants in microphthalmia-associated transcription factor (MITF) and two variants in Paired Box 3 (PAX3) have been identified to explain this phenotype. A splashed white Thoroughbred stallion, whose sire and dam were not patterned, was hypothesized to have a de novo variant leading to his white coat pattern. A whole-genome sequencing candidate gene approach identified two single nucleotide variants (SNVs) in SOX10, four SNVs in MITF and a 2.3 kb deletion in MITF with the alternative allele present in this stallion but absent in the other 18 horses analyzed. All six SNVs were annotated as modifiers and were not further considered. The deletion in MITF (NC_009159.3:g.21555811_21558139delinsAAAT) encompasses exon 9 encoding a part of the helix-loop-helix domain required for DNA binding. Sanger sequencing and parentage testing confirmed that this deletion was a de novo mutation of maternal origin. Consistent with the published nomenclature, we denote this likely causal variant as SW8. Genotyping three of this stallion's offspring identified SW8 only in the nearly all-white foal that was confirmed deaf by brainstem auditory evoked response testing. This foal was also a compound heterozygote for dominant white variants (W20/W22), but to date, W variants alone have not been connected to deafness. SW8 marks the fourth de novo MITF variant in horses reported to cause white patterning. The link between deafness and all MITF variants with and without other variants impacting melanocyte development and function needs to be further explored.

A case of hypocholesterolemia under research

Primary hypocholesterolemia (or hypobetalipoproteinemia) is a rare disorder of lipoprotein metabolism that may be due to a polygenic predisposition or a monogenic disease. Among these, it is possible to differentiate between symptomatic and asymptomatic forms, in which, in the absence of secondary causes, the initial clinical suspicion is plasma ApoB levels below the 5th percentile of the distribution by age and sex. Here we describe the differential diagnosis of a case of asymptomatic hypocholesterolemia. We studied proband’s clinical data, the lipid profile of the proband and her relatives and the clinical data of the family relevant to carry out the differential diagnosis. We performed a genetic study as the diagnostic test. The information obtained from the differential diagnosis suggested a heterozygous hypobetalipoproteinemia due to PCSK9 loss-of-function variants. The diagnostic test revealed, in the proband, the presence of a heterozygous PCSK9 frame-shift variant of a maternal origin. Plasma levels of LDL cholesterol and PCSK9 of the patient and her relatives were compatible with the segregation of the variant revealed. In conclusion, the diagnostic test performed confirmed the suspected diagnosis of the proband as asymptomatic familial hypobetalipoproteinemia due to a loss-of-function variant in the PCSK9 gene.

Phylogenetic Analysis of Russian Native Sheep Breeds Based on mtDNA Sequences.

Eurasia is represented by all climatic zones and various environments. A unique breed variety of farm animals has been developed in Russia, whose territory covers a large area of the continent. A total of 69 local breeds and types of dairy, wool, and meat sheep (Ovis aries) are maintained here. However, the genetic diversity and maternal origin of these local breeds have not been comprehensively investigated. In this study, we describe the diversity and phylogeny of Russian sheep breeds inhabiting different geographical regions based on the analysis of complete sequences of mitochondrial genomes (mtDNA). Complete mtDNA sequences of the studied sheep were obtained using next-generation sequencing technology (NGS). All investigated geographical groups of sheep were characterized by high haplotype (Hd = 0.9992) and nucleotide diversity (π = 0.00378). Analysis of the AMOVA results showed that genetic diversity was majorly determined by within-population differences (77.87%). We identified 128 haplotypes in all studied sheep. Haplotypes belonged to the following haplogroups: B (64.8%), A (28.9%), C (5.5%), and D (0.8%). Haplogroup B was predominant in the western part of Russia. A high level of mtDNA polymorphism in the studied groups of local sheep indicates the presence of a significant reserve of unique genotypes in Russia, which is to be explored.

Quantification of Female Chimeric Cells in the Tonsils of Male Children and Their Determinants.

The factors influencing mother-to-child cell trafficking and persistence over children's lives have yet to be established. The quantification of maternal microchimerism was previously reported through HLA-based approaches, which introduced bias regarding the tolerogenic environment. We aimed to identify cells of maternal origin irrespective of the HLA repertoire and to ascertain the determinants of microchimeric cells. This case-control study enrolled 40 male infants attending pediatric surgery from January 2022 to October 2022. Female cells were quantified in infants' tonsil tissue by using cytogenetic fluorescent in situ hybridization (FISH) coupled with optimized automated microscopy. Out of the 40 infants, half (47.4%) had been breastfed for more than one month, a quarter for less a month, and 10 children (26.3%) were never breastfed. XX cells were observed in male tonsils in two-thirds of participants at a median density of 5 cells per 100,000 cells. In univariate analyses, child age was negatively associated with a high female cell density. In exploratory multivariate analyses, previous breastfeeding is a likely determinant of the persistence of these cells in the host, as well as the rank among siblings. Part of the benefit of breastmilk for child health may therefore be driven by breastfeeding-related microchimerism.

Parental effects on offspring sex ratio in the Numbat (Myrmecobius fasciatus): does captivity influence paternal sex allocation?

Sex allocation theories predict that under different ecological conditions the production of sons and daughters will affect parental fitness differently. Skewed offspring sex ratios often occur under captive conditions where individuals are exposed to nutritional and social conditions that differ from nature. Here, we analyzed 29 years of offspring sex ratio data from a captive population of an endangered marsupial, the Numbat (Myrmecobius fasciatus). We partitioned variation in offspring sex ratio based on parental origin (captive- vs. wild-bred), parental weight, maternal age, and maternal reproductive history. Our analyses revealed no effect of parental weight or maternal origin on offspring sex ratio-however, there was a significant effect of paternal origin. Data visualization indicated that captive-bred males tended to produce male-biased litters. We discuss the result in relation to recent studies that have shown that male mammals have the capacity to be arbiters of sex allocation and highlight candidate mechanisms, but consider it with caution due to the small sample size from which the result was derived. We performed a population viability analysis (PVA) to explore the potential impact of a sex ratio skew on the sustainability of the captive Numbat population under hypothetical scenarios. Our PVA revealed that supplementation with wild individuals is critical to the persistence of the captive Numbat population and that a biased sex ratio will lead to extinction of the captive colony under certain conditions. Overall, our study demonstrates that covert sex ratio skews can persist undetected in captive populations, which have the potential to become impactful and compromise population sustainability under changed management processes.

Association between TGFβ1 Levels in Cord Blood and Weight Progress in the First Year of Life.

Transforming growth factor beta-1 (TGFβ1) is an adipokine secreted from adipose tissue, placental tissue and immune cells with a role in cell proliferation, cell apoptosis and angiogenic proliferation. The role of TGFβ1 in pregnancy and child growth and the source of cord TGFβ1 are yet unknown. In this study, we sought to clarify the correlation of TGFβ1 levels with parameters of intrauterine growth and child growth during the first year of life, and to determine whether their source is primarily of fetal or maternal origin. Serum samples and anthropometric measurements were obtained from the LIFE Child cohort of 79 healthy mother-child pairs. Measurements were conducted using enzyme-linked immunosorbent assays. Statistical analyses including Mann-Whitney U-test, correlation analyses and linear regression analyses were performed using GraphPad Prism and R. TGFβ1 levels were significantly higher in cord than in maternal serum, suggesting a fetal origin. Multivariate regression analyses revealed strong positive associations between cord TGFβ1 levels at birth and child weight at U6. Furthermore, cord TGFβ1 was significantly correlated with child weight at approximately one year of age. An increase of 10,000 pg/mL in cord TGFβ1 concentrations at birth was associated with a higher body weight of 201 g at roughly one year of age when adjusted for sex.