Perturbed development of calb2b expressing dI6 interneurons and motor neurons underlies locomotor defects observed in calretinin knock-down zebrafish larvae.

Calcium binding proteins are essential for neural development and cellular activity. Calretinin, encoded by calb2a and calb2b, plays a role during early zebrafish development and has been proposed as a marker for distinct neuronal populations within the locomotor network. We generated a calb2b:hs:eGFP transgenic reporter line to characterize calretinin expressing cells in the developing spinal cord and describe morphological and behavioral defects in calretinin knock-down larvae. eGFP was detected in primary and secondary motor neurons, as well as in dI6 and V0v interneurons. Knock-down of calretinin lead to disturbed development of motor neurons and dI6 interneurons, revealing a crucial role during early development of the locomotor network. Primary motor neurons showed delayed axon outgrowth and the distinct inhibitory CoLo neurons, originating from the dI6 lineage, were absent. These observations explain the locomotor defects we observed in calretinin knock-down animals where the velocity, acceleration and coordination were affected during escapes. Altogether, our analysis suggests an essential role for calretinin during the development of the circuits regulating escape responses and fast movements within the locomotor network.

Identification and characterization of single nucleotide polymorphisms in DMRT3 gene in Indian horse (Equus caballus) and donkey (Equus asinus) populations.

Equines' ability in racing and riding as well as gaitedness have influenced the human civilization. Aim of this study was to identify and characterize the novel polymorphisms or SNPs in DMRT3 gene in Indian horse and donkey breeds. In this study, the DMRT3 gene was sequenced and characterized in 72 Indian horses' and 33 Indian donkeys' samples. One SNP (A > C) at 878 was found in studied horses while identical SNPs (A > C) at two different nucleotide positions i.e., 878 and 942 in DMRT3 gene (chromosome 23) were observed in studied Indian donkey breeds. Horses and donkeys both have a non-synonymous mutation (A > C) at nucleotide 878 (codon 61) that converts a Stop codon (TAG > TCG) to coding codon Serine, whereas donkeys have a synonymous mutation at nucleotide 942 (codon 82) that converts Serine (TCA > TCC) into Serine. A phylogenetic tree indicated that the DMRT3 gene was equally distributed among the equine breeds. Most of the donkey breeds have been shown high levels of genetic diversity while horse breeds and Halari donkey showed the least genetic diversity. Mutation in DMRT3 has a major impact on gaitedness in horses and is presented at a high frequency in gaited breeds and in horses breed for harness racing.

Neuronal Circuits That Control Rhythmic Pectoral Fin Movements in Zebrafish.

The most basic form of locomotion in limbed vertebrates consists of alternating activities of the flexor and extensor muscles within each limb coupled with left/right limb alternation. Although larval zebrafish are not limbed, their pectoral fin movements exhibit the following fundamental aspects of this basic movement: abductor/adductor alternation (corresponding to flexor/extensor alternation) and left/right fin alternation. Because of the simplicity of their movements and the compact neural organization of their spinal cords, zebrafish can serve as a good model to identify the neuronal networks of the central pattern generator (CPG) that controls rhythmic appendage movements. Here, we set out to investigate neuronal circuits underlying rhythmic pectoral fin movements in larval zebrafish, using transgenic fish that specifically express GFP in abductor or adductor motor neurons (MNs) and candidate CPG neurons. First, we showed that spiking activities of abductor and adductor MNs were essentially alternating. Second, both abductor and adductor MNs received rhythmic excitatory and inhibitory synaptic inputs in their active and inactive phases, respectively, indicating that the MN spiking activities are controlled in a push-pull manner. Further, we obtained the following evidence that dmrt3a-expressing commissural inhibitory neurons are involved in regulating the activities of abductor MNs: (1) strong inhibitory synaptic connections were found from dmrt3a neurons to abductor MNs; and (2) ablation of dmrt3a neurons shifted the spike timing of abductor MNs. Thus, in this simple system of abductor/adductor alternation, the last-order inhibitory inputs originating from the contralaterally located neurons play an important role in controlling the firing timings of MNs.SIGNIFICANCE STATEMENT Pectoral fin movements in larval zebrafish exhibit fundamental aspects of basic rhythmic appendage movement: alternation of the abductor and adductor (corresponding to flexor-extensor alternation) coupled with left-right alternation. We set out to investigate the neuronal circuits underlying rhythmic pectoral fin movements in larval zebrafish. We showed that both abductor and adductor MNs received rhythmic excitatory and inhibitory synaptic inputs in their active and inactive phases, respectively. This indicates that MN activities are controlled in a push-pull manner. We further obtained evidence that dmrt3a-expressing commissural inhibitory neurons exert an inhibitory effect on abductor MNs. The current study marks the first step toward the identification of central pattern generator organization for rhythmic fin movements.

Genome-wide scans for signatures of selection in Mangalarga Marchador horses using high-throughput SNP genotyping.

BACKGROUND: The detection of signatures of selection in genomic regions provides insights into the evolutionary process, enabling discoveries regarding complex phenotypic traits. In this research, we focused on identifying genomic regions affected by different selection pressures, mainly highlighting the recent positive selection, as well as understanding the candidate genes and functional pathways associated with the signatures of selection in the Mangalarga Marchador genome. Besides, we seek to direct the discussion about genes and traits of importance in this breed, especially traits related to the type and quality of gait, temperament, conformation, and locomotor system. RESULTS: Three different methods were used to search for signals of selection: Tajima's D (TD), the integrated haplotype score (iHS), and runs of homozygosity (ROH). The samples were composed of males (n = 62) and females (n = 130) that were initially chosen considering well-defined phenotypes for gait: picada (n = 86) and batida (n = 106). All horses were genotyped using a 670 k Axiom® Equine Genotyping Array​ (Axiom MNEC670). In total, 27, 104 (chosen), and 38 candidate genes were observed within the signatures of selection identified in TD, iHS, and ROH analyses, respectively. The genes are acting in essential biological processes. The enrichment analysis highlighted the following functions: anterior/posterior pattern for the set of genes (GLI3, HOXC9, HOXC6, HOXC5, HOXC4, HOXC13, HOXC11, and HOXC10); limb morphogenesis, skeletal system, proximal/distal pattern formation, JUN kinase activity (CCL19 and MAP3K6); and muscle stretch response (MAPK14). Other candidate genes were associated with energy metabolism, bronchodilator response, NADH regeneration, reproduction, keratinization, and the immunological system. CONCLUSIONS: Our findings revealed evidence of signatures of selection in the MM breed that encompass genes acting on athletic performance, limb development, and energy to muscle activity, with the particular involvement of the HOX family genes. The genome of MM is marked by recent positive selection. However, Tajima's D and iHS results point also to the presence of balancing selection in specific regions of the genome.

Characterization of Dmrt3-Derived Neurons Suggest a Role within Locomotor Circuits.

Neuronal networks within the spinal cord, collectively known as the central pattern generator (CPG), coordinate rhythmic movements underlying locomotion. The transcription factor doublesex and mab-3-related transcription factor 3 (DMRT3) is involved in the differentiation of the dorsal interneuron 6 class of spinal cord interneurons. In horses, a non-sense mutation in the Dmrt3 gene has major effects on gaiting ability, whereas mice lacking the Dmrt3 gene display impaired locomotor activity. Although the Dmrt3 gene is necessary for normal spinal network formation and function in mice, a direct role for Dmrt3-derived neurons in locomotor-related activities has not been demonstrated. Here we present the characteristics of the Dmrt3-derived spinal cord interneurons. Using transgenic mice of both sexes, we characterized interneurons labeled by their expression of Cre driven by the endogenous Dmrt3 promoter. We used molecular, retrograde tracing and electrophysiological techniques to examine the anatomical, morphological, and electrical properties of the Dmrt3-Cre neurons. We demonstrate that inhibitory Dmrt3-Cre neurons receive extensive synaptic inputs, innervate surrounding CPG neurons, intrinsically regulate CPG neuron's electrical activity, and are rhythmically active during fictive locomotion, bursting at frequencies independent to the ventral root output. The present study provides novel insights on the character of spinal Dmrt3-derived neurons, data demonstrating that these neurons participate in locomotor coordination.SIGNIFICANCE STATEMENT In this work, we provide evidence for a role of the Dmrt3 interneurons in spinal cord locomotor circuits as well as molecular and functional insights on the cellular and microcircuit level of the Dmrt3-expressing neurons in the spinal cord. Dmrt3 neurons provide the first example of an interneuron population displaying different oscillation frequencies. This study presents novel findings on an under-reported population of spinal cord neurons, which will aid in deciphering the locomotor network and will facilitate the design and development of therapeutics for spinal cord injury and motor disorders.

Identification of a candidate enhancer for DMRT3 involved in spastic cerebral palsy pathogenesis.

Cerebral palsy (CP) is a major neuronal disease and the most common movement disorder in children. Although environmental factors leading to CP have been greatly investigated, the genetic mechanism underlying CP is not well understood. Here we focused on two clinical reports that characterized a deletion involving the KANK1 gene locus in the 9p24.3 region. One report shows spastic CP and the other shows no spastic CP phenotype. Based on the epigenetic status and evolutionary conservation, we first found a functional genomic element at the noncoding region that was deleted only in patients with spastic CP. This element contains the retinoic acid receptor/retinoid X receptor (RAR/RXR) complex-binding motif that is widely conserved among placental mammals. RAR/RXR ChIP-seq data from mouse F9 embryonal carcinoma cells that were treated with trans-retinoic acids showed that the element has a binding ability. In addition, data regarding chromosome conformation capture from mouse neural progenitor and ES cells suggested that the element spatially interacts with the Doublesex and mab-3 related transcription factor 3 (Dmrt3) gene promoter that is located approximately 120 kb downstream of the RAR/RXR-binding site. Dmrt3 is detected in the developing mouse forebrain and in some interneurons in the spinal cord, and it works as a locomotion coordinator in horses and mice. Thus, the deletion of the cis-regulatory element for DMRT3 in humans may cause impaired development of the forebrain and gait abnormalities, resulting in spastic CP. In conclusion, this study provides new mechanistic insights into the genetic basis of CP.

Curcumin Inhibits the Progression of Non-small Cell Lung Cancer by Regulating DMRT3/SLC7A11 Axis.

Non-small cell lung cancer (NSCLC) is a fatal malignancy all over the world. Emerging studies have shown that curcumin might repress NSCLC progression by regulating ferroptosis, but the underlying mechanism remains unclear. 16HBE, LK-2, and H1650 cell viability was detected using Cell Counting Kit-8 assay. LK-2 and H1650 cell proliferation, apoptosis, and angiopoiesis were measured using 5-ethynyl-2'-deoxyuridine, flow cytometry, and tube formation assay. Superoxide dismutase, Malondialdehyde, Glutathione, and lactate dehydrogenase levels in LK-2 and H1650 cells were examined using special assay kits. Fe+ level was assessed using an iron assay kit. Doublesex and Mab-3 related Transcription Factor 3 (DMRT3) and solute carrier family 7 member 11 (SLC7A11) protein levels were detected using western in NSCLC tissues, adjacent matched normal tissues, 16HBE cells, LK-2 cells, H1650 cells, and xenograft tumor tissues. Glutathione peroxidase 4, Acyl-CoA Synthetase Long Chain Family Member 4, and transferrin receptor 1 protein levels in LK-2 and H1650 cells were examined by western blot assay. DMRT3 and SLC7A11 levels were determined using real-time quantitative polymerase chain reaction. After JASPAR prediction, binding between DMRT3 and SLC7A11 promoter was verified using Chromatin immunoprecipitation and dual-luciferase reporter assays in LK-2 and H1650 cells. Role of curcumin on NSCLC tumor growth was assessed using the xenograft tumor model in vivo. Curcumin blocked NSCLC cell proliferation and angiopoiesis, and induced apoptosis and ferroptosis. DMRT3 or SLC7A11 upregulation partly abolished the suppressive role of curcumin on NSCLC development. In mechanism, DMRT3 was a transcription factor of SLC7A11 and increased the transcription of SLC7A11 via binding to its promoter region. Curcumin inhibited NSCLC growth in vivo by modulating DMRT3. Curcumin might constrain NSCLC cell malignant phenotypes partly through the DMRT3/SLC7A11 axis, providing a promising therapeutic strategy for NSCLC.

Medaka (Oryzias latipes) Dmrt3a Is Involved in Male Fertility.

Research across various species has demonstrated that the doublesex and mab-3-related transcription factor 3 (dmrt3) plays pivotal roles in testis development. However, the precise molecular mechanisms of dmrt3 remain unclear. In this study, we investigated the role of dmrt3 (dmrt3a) in testis development using the model organism medaka (Oryzias latipes). SqRT-PCR and ISH analyses revealed that dmrt3a is predominantly expressed in the testis, especially in the spermatid and spermatozoon. Using CRISPR/Cas9, we generated two dmrt3a homozygous mutants (-8 bp and -11 bp), which exhibited significantly reduced fertilization rates and embryo production. Additionally, the number of germ cells and sperm motility were markedly decreased in the dmrt3a mutants, manifesting as the symptoms of asthenozoospermia and oligozoospermia. Interestingly, RNA-Seq analysis showed that the deficiency of dmrt3a could lead to a significant downregulation of numerous genes related to gonadal development and severe disruptions in mitochondrial function. These results suggested that dmrt3a is essential for spermatogenesis and spermatozoa energy production. This paper provides new insights and perspectives for further exploring the molecular mechanisms underlying spermatogenesis and addressing male reproductive issues.

DMRT3-mediated lncRNA OIP5-AS1 promotes the pyroptosis of bronchial epithelial cells by binding with EIF4A3 to enhance YAP mRNA stability.

Asthma is featured by persistent airway inflammation. Long noncoding RNAs (lncRNAs) are reported to play critical roles in asthma. However, the function of Opa interacting protein 5-antisense 1 (OIP5-AS1) in pyroptosis during the development of asthma remains unexplored. The blood samples of asthma patients (n = 32) as well as the baseline characteristics of asthma patients or healthy people were collected. An in vivo model of asthma was established using house dust mites (HDM). To mimic asthma in vitro, BEAS-2B cells were treated with HDM. Cell pyroptosis and apoptosis were examined by flow cytometry. The levels of interleukin-1 beta (IL-1ß) and interleukin-18 (IL-18) were detected by enzyme-linked immunosorbent assay (ELISA). The binding among messenger RNAs (mRNAs) was assessed by chromatin immunoprecipitation (ChIP), dual luciferase report assay, RNA immunoprecipitation (RIP), co-immunoprecipitation (Co-IP), and RNA pull-down assay, respectively. The cellular localization was observed by fluorescence in situ hybridization (FISH) staining. The level of OIP5-AS1 was upregulated in asthma patients. HDM induced pyroptosis and increased the levels of IL-18, IL-1ß, and lactate dehydrogenase (LDH) in BEAS-2B cells, which was obviously reversed by OIP5-AS1 knockdown. Consistently, the expressions of NOD-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), c-caspase 1, and pyroptosis-related gasdermin D-1 (GSDMD-1) in BEAS-2B cells were upregulated by HDM treatment, while these phenomena were partially abolished by silencing of OIP5-AS1. Moreover, HDM promoted the progression of asthma in vivo, which was rescued by the downregulation of OIP5-AS1. OIP5-AS1 silencing decreased HDM-induced cell pyroptosis by inactivation of NLRP3. More importantly, OIP5-AS1 promoted the mRNA stability of yes-associated protein (YAP) via binding with eukaryotic translation initiation factor 4A3 (EIF4A3), and OIP5-AS1 was transcriptionally upregulated by doublesex and mab-3 related transcription factor 3 (DMRT3). DMRT3-mediated OIP5-AS1 aggravated the progression of asthma by mediation of the EIF4A3/YAP axis, which might provide a new therapeutic strategy against asthma.

Comprehensive Analysis of DMRT3 as a Potential Biomarker Associated with the Immune Infiltration in a Pan-Cancer Analysis and Validation in Lung Adenocarcinoma.

Doublesex and Mab-3 related Transcription Factor 3 (DMRT3) is associated with the prognosis of some tumors. It is possible to explore the role of DMRT3 in the cancer process using bioinformatic approaches and experimental validation. We comprehensively explored the clinical and immunological characteristics of DMRT3. The DMRT3 expression is abnormal in human cancers and correlates with clinical staging. A high DMRT3 expression is significantly associated with poor overall survival (OS) in KIRC, KIRP, LUAD, and UCEC. Amplification was the greatest frequency of the DMRT3 alterations in pan-cancer. The OS was significantly lower in the DMRT3 altered group than in the DMRT3 unaltered group (P = 0.0276). The DMRT3 expression was significantly associated with MSI in three cancer types and TMB in six cancer types. The DMRT3 expression was significantly correlated with the level of the immune cell infiltration and the immune checkpoint genes. The DMRT3 was involved in some pathways in pan-cancer. DMRT3 may play a role in chemotherapy and may be associated with chemoresistance. A ceRNA network of KCNQ1OT1/miR-335-5p/DMRT3 was constructed in LUAD. DMRT3 was significantly upregulated in the LUAD cell lines. DMRT3 was aberrantly expressed in pan-cancer and may promote tumorigenesis and progression via different mechanisms. DMRT3 can be used as a therapeutic target to treat cancer in humans.

Profiling of genetic markers useful for breeding decision in Selle Francais horse.

Genetic disorders are recognised as hereditary diseases with the most significant economic impact on horse breeding, causing important foal losses, costs of treatments of horses, and maintenance of the mare during the pregnancy. The Selle Francais horses are recognized in many countries and are showing great results in equestrian sports around the world (dressage, show jumping and eventing). The study aimed to detect the presence of three mutant alleles associated with inherited diseases including Fragile Foal Syndrome (FFS), Cerebellar Abiotrophy (CA), Polysaccharide Storage Myopathy (PSSM1) and variant impacting gait type in DMRT3. This trait is important for breeding decision in Selle Francais horses and sheds new light on genetic potential and risks on this breed. The genotyping was performed on 91 Selle Francais horses using PCR-RFLP (for POLD1; GYS1 and DMRT3 genes) and PCR-ACRS (TOE1 gene) methods. The presented report indicated the presence of mutant allele A casual for PSSM1 and allele T associated with FFS syndrome occurrence, in 4% and 6% of analysed horses, respectively. Regarding CA, the present survey did not register any cases of this genetic disorder in Selle Francais horses. Our results show also that about 1% of all the Sell Francais horses studied carry the A allele of DMRT3 gene. The present findings have provided data for these fulness of monitoring genetic diseases and gait type in the investigated breed to avoid losses of offspring.

Whole-Genome Sequence Analysis Reveals the Origin of the Chakouyi Horse.

The Chakouyi horse is an ancient Chinese indigenous horse breed distributed in Gansu Province in northwestern China, and is also one of the key breeds protected by the government. However, the origin of the Chakouyi horse remains unclear. As it is distributed in a key region of the Silk Road, it was speculated that the origin of the Chakouyi horse might involve the foreign horse breeds found along this ancient commercial artery. In this study, whole-genome resequencing data of 12 horse breeds, including both indigenous and foreign horses, were applied to reveal the genetic relationships between the Chakouyi horse and other breeds, as well as the ancestry of this ancient breed. An analysis of the population structure and admixture showed that there is no close genetic affinity between the Chakouyi horse and the foreign horses while Chinese indigenous horse populations were grouped together in accordance with their geographic locations, and the Chakouyi horse showed a closer relationship with Kazak horses, Mongolian horses, and Tibetan horses. The results from the ancestral composition prediction indicated that the Kazak horse and the Mongolian horse might be two ancestors of the Chakouyi horse. Furthermore, the genome-wide selection signature analysis revealed that the DMRT3 gene was positively selected in the Chakouyi horse and related to the gait trait of the breed. Our results provide insights into the native origin of the Chakouyi horse and indicate that Kazak and Mongolian horses played important roles in the formation of the Chakouyi horse. Genetic communication between the Chakouyi horse and other horse populations could be attributed, at least partially, to population migrations and trade activities along the ancient commercial routes.

Transcriptome Analysis Identifies Doublesex and Mab-3 Related Transcription Factor (DMRT3) in Nasal Polyp Epithelial Cells of Patients Suffering from Non-Steroidal Anti-Inflammatory Drug-Exacerbated Respiratory Disease (AERD).

BACKGROUND: Aspirin-exacerbated respiratory disease (AERD) is a syndrome characterised by chronic rhinosinusitis, nasal polyps, asthma and aspirin intolerance. An imbalance of eicosanoid metabolism with anover-production of cysteinyl leukotrienes (CysLTs) has been associated with AERD. However, the precise mechanisms underlying AERD are unknown. OBJECTIVE: To establish the transcriptome of the nasal polyp airway epithelial cells derived from AERD patients to discover gene expression patterns in this disease. METHODS: Nasal airway epithelial cells were isolated from 12 AERD polyps and 8 AERD non-polyp nasal mucosa samples as controls from the same subjects. Utilising the Illumina HiSeq 2500 platform, RNA samples were sequenced. Potential gene candidate DMRT3 was selected from the differentially-expressed genes for validation. RESULTS: Comparative transcriptome profiling of nasal epithelial cells was accomplished in AERD. A total of 20 genes had twofold mean regulation expression differences or greater. In addition, 8 genes were upregulated, including doublesex and mab-3 related transcription factor 3 (DMRT3), and 12 genes were downregulated. Differentially regulated genes comprised roles in inflammation, defence and immunity. Metabolic process and embryonic development pathways were significantly enriched. Enzyme-linked immune sorbent assay (ELISA) results of DMRT3 in AERD patients were significantly upregulated compared to controls (p = 0.03). Immunohistochemistry (IHC) of AERD nasal polyps localised DMRT3 and was predominantly released in the airway epithelia. CONCLUSION: Findings suggest that DMRT3 could be potentially involved in nasal polyp development in AERD patients. Furthermore, several genes are downregulated, hinting at the dedifferentiation phenomenon in AERD polyps. However, further studies are imperative to confirm the exact mechanism of polyp formation in AERD patients.

Single Cell Transcriptomic Analysis of Spinal Dmrt3 Neurons in Zebrafish and Mouse Identifies Distinct Subtypes and Reveal Novel Subpopulations Within the dI6 Domain.

The spinal locomotor network is frequently used for studies into how neuronal circuits are formed and how cellular activity shape behavioral patterns. A population of dI6 interneurons, marked by the Doublesex and mab-3 related transcription factor 3 (Dmrt3), has been shown to participate in the coordination of locomotion and gaits in horses, mice and zebrafish. Analyses of Dmrt3 neurons based on morphology, functionality and the expression of transcription factors have identified different subtypes. Here we analyzed the transcriptomes of individual cells belonging to the Dmrt3 lineage from zebrafish and mice to unravel the molecular code that underlies their subfunctionalization. Indeed, clustering of Dmrt3 neurons based on their gene expression verified known subtypes and revealed novel populations expressing unique markers. Differences in birth order, differential expression of axon guidance genes, neurotransmitters, and their receptors, as well as genes affecting electrophysiological properties, were identified as factors likely underlying diversity. In addition, the comparison between fish and mice populations offers insights into the evolutionary driven subspecialization concomitant with the emergence of limbed locomotion.

Characterization of Individual Projections Reveal That Neuromasts of the Zebrafish Lateral Line are Innervated by Multiple Inhibitory Efferent Cells.

The zebrafish lateral line is a sensory system used to detect changes in water flow. It is comprized of clusters of superficial hair cells called neuromasts. Modulation occurs via excitatory and inhibitory efferent neurons located in the brain. Using mosaic transgenic labeling we provide an anatomical overview of the lateral line projections made by individual inhibitory efferent neurons in 5-day old zebrafish larvae. For each hemisphere we estimate there to be six inhibitory efferent neurons located in two different nuclei. Three distinct cell types were classified based on their projections; to the anterior lateral line around the head, to the posterior lateral line along the body, or to both. Our analyses corroborate previous studies employing back-fills, but our transgenic labeling allowed a more thorough characterization of their morphology. We found that individual inhibitory efferent cells connect to multiple neuromasts and that a single neuromast is connected by multiple inhibitory efferent cells. The efferent axons project to the sensory ganglia and follow the sensory axon tract along the lateral line. Time-lapse imaging revealed that inhibitory efferent axons do not migrate with the primordium as the primary sensory afferent does, but follow with an 8-14 h lag. These data bring new insights into the formation of a sensory circuit and support the hypothesis that different classes of inhibitory efferent cells have different functions. Our findings provide a foundation for future studies focussed toward unraveling how and when sensory perception is modulated by different efferent cells.

Distribution of the mutant allele of the DMRT3 gene associated with ambling gaits in Japanese native horse populations.

There are currently eight native horse populations in Japan, namely, Hokkaido, Kiso, Noma, Taishu, Misaki, Tokara, Miyako, and Yonaguni horses. Since locomotion traits, including gaitedness, are important for riding and packing horses, the genetic properties associated with these traits could be informative for understanding the characteristics and history of these horses. In this study, we investigated the distribution of the mutant allele of DMRT3 gene (DMRT3:p.Ser301Ter) associated with ambling gaits in the Japanese native horse. We also examined haplotypes of SNPs in the 83-kb region including DMRT3 gene by genotyping four SNPs in this region. The results revealed the presence of DMRT3:p.Ser301Ter in the Hokkaido and Yonaguni populations at allele frequencies of 0.18 and 0.02, respectively, and the observed haplotype associated with DMRT3:p.Ser301Ter was estimated as the most common haplotype in the horses in the world. Since DMRT3:p.Ser301Ter has been hypothesized to spread across Eurasian continent from Medieval England after 850 to 900 CE, our findings of the presence of DMRT3:p.Ser301Ter with the common haplotype in the Japanese native horses will provide a new insight into the history of the Japanese native horse, such as considerable level of gene flow from Eurasian continent after 850 to 900 CE.

Genetic analysis of a Taiwanese family identifies a DMRT3-OAS3 interaction that is involved in human sexual differentiation through the regulation of ESR1 expression.

OBJECTIVE: To identify the genetic etiology of recurrent disorders of sex development (DSDs) in a Taiwanese family with 46,XY sex reversal and hypospadias. DESIGN: Genetic and functional studies. SETTING: Academic hospital. PATIENT(S): A three-generation family consisting of 22 members, with eight cases of 46,XY DSD, of whom four have 46,XY male-to-female sex reversal and four are 46,XY males with hypospadias. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Results of exome sequencing and in vitro protein and RNA analyses. RESULT(S): All patients with DSDs were found to carry heterozygous missense mutations in the doublesex and mab-3-related transcription factor 3 (DMRT3; rs187176004, c.A815C, p.K272T) and 2',5'-oligoadenylate synthetase 3 (OAS3; rs16942374, c.G2606A, p.R869H) genes. The DMRT3 mutation increased estrogen receptor 1 (ESR1) expression. Upon binding with the OAS3-RNase L complex, wild-type DMRT3 promoted degradation of ESR1 mRNA. However, the DMRT3A815C-OAS3G2606A complex interacted less strongly with ESR1 mRNA and RNase L, ultimately preventing ESR1 mRNA degradation. The interactions between DMRT3, OAS3, and RNase L were confirmed in the patients' testis. CONCLUSION(S): Our results indicate that DMRT3 and OAS3 are involved in human DSDs by controlling ESR1 expression.

Functional Diversity of Glycinergic Commissural Inhibitory Neurons in Larval Zebrafish.

Commissural inhibitory neurons in the spinal cord of aquatic vertebrates coordinate left-right body alternation during swimming. Their developmental origin, however, has been elusive. We investigate this by comparing the anatomy and function of two commissural inhibitory neuron types, dI6dmrt3a and V0d, derived from the pd6 and p0 progenitor domains, respectively. We find that both of these commissural neuron types have monosynaptic, inhibitory connections to neuronal populations active during fictive swimming, supporting their role in providing inhibition to the contralateral side. V0d neurons tend to fire during faster and stronger movements, while dI6dmrt3a neurons tend to fire more consistently during normal fictive swimming. Ablation of dI6dmrt3a neurons leads to an impairment of left-right alternating activity through abnormal co-activation of ventral root neurons on both sides of the spinal cord. Our results suggest that dI6dmrt3a and V0d commissural inhibitory neurons synergistically provide inhibition to the opposite side across different swimming behaviors.

Population Genetic Analysis of the Estonian Native Horse Suggests Diverse and Distinct Genetics, Ancient Origin and Contribution from Unique Patrilines.

The Estonian Native Horse (ENH) is a medium-size pony found mainly in the western islands of Estonia and is well-adapted to the harsh northern climate and poor pastures. The ancestry of the ENH is debated, including alleged claims about direct descendance from the extinct Tarpan. Here we conducted a detailed analysis of the genetic makeup and relationships of the ENH based on the genotypes of 15 autosomal short tandem repeats (STRs), 18 Y chromosomal single nucleotide polymorphisms (SNPs), mitochondrial D-loop sequence and lateral gait allele in DMRT3. The study encompassed 2890 horses of 61 breeds, including 33 ENHs. We show that the expected and observed genetic diversities of the ENH are among the highest within 52 global breeds, and the highest among 8 related Northern European ponies. The genetically closest breeds to the ENH are the Finn Horse, and the geographically more distant primitive Hucul and Konik. ENH matrilines are diverse and relate to draught and Pontic-Caspian breeds. ENH patrilines relate to draught breeds, and to a unique haplogroup not described before. None of the 33 ENHs carried the "gait" mutation, but the mutation was found in 2 Huculs. The study demonstrates that the ENH is a genetically distinct and diverse breed of ancient origin with no notable pressure of selective breeding.

Genotype distribution and allele frequencies of the genes associated with body composition and locomotion traits in Myanmar native horses.

Myanmar native horses are small horses used mainly for drafting carts or carriages in rural areas and packing loads in mountainy areas. In the present study, we investigated genotype distributions and allele frequencies of the LCORL/NCAPG, MSTN and DMRT3 genes, which are associated with body composition and locomotion traits of horses, in seven local populations of Myanmar native horses. The genotyping result of LCORL/NCAPG showed that allele frequencies of C allele associated with higher withers height ranged from 0.08 to 0.27, and 0.13 in average. For MSTN, allele frequencies of C allele associated with higher proportion of Type 2B muscular fiber ranged from 0.05 to 0.23, and 0.09 in average. For DMRT3, allele frequencies of A allele associated with ambling gait ranged from 0 to 0.04, and 0.01 in average. The presences of the minor alleles of these genes at low frequencies suggest a possibility that these horse populations have not been under strong selection pressure for particular locomotion traits and body composition. Our findings of the presence of these minor alleles in Southeast Asian native horses are also informative for considering the origins of these minor alleles associated with body composition and locomotion traits in horse populations.