Bone lesions and intestinal barrier disruption caused by the isolated novel goose parvovirus infection in ducks.

Short beak and dwarfism syndrome (SBDS) is attributed to Novel Goose Parvovirus (NGPV), which has inflicted significant economic losses on farming in China. Despite its significant impact, limited research has been conducted on the pathogenesis of this disease. The SD strain, a parvovirus variant isolated from ducks in Shandong province, was identified and characterized in our study. Phylogenetic analysis and sequence comparisons confirmed the classification of the SD strain as a member of NGPV. Based on this information, we established an animal model of SBDS by inoculating Cherry Valley ducks with the SD strain. Our findings indicate that infection with the SD strain leads to a reduction in body weight, beak length, width, and tibia length. Notably, significant histopathological alterations were observed in the thymus, spleen, and intestine of the infected ducks. Furthermore, the SD strain induces bone disorders and inflammatory responses. To evaluate the impact of NGPV on intestinal homeostasis, we performed 16S rDNA sequencing and gas chromatography to analyze the composition of intestinal flora and levels of short-chain fatty acids (SCFAs) in the cecal contents. Our findings revealed that SD strain infection induces dysbiosis in cecal microbial and a decrease in SCFAs production. Subsequent analysis revealed a significant correlation between bacterial genera and the clinical symptoms in NGPV SD infected ducks. Our research providing novel insights into clinical pathology of NGPV in ducks and providing a foundation for the research of NGPV treatment targeting gut microbiota.

The tale of the rattle: Using rattle size to understand growth and sexual dimorphism in an insular population of rattlesnakes (Crotalus oreganus caliginis).

Islands have played a key role in our understanding of rapid evolution. A large body of literature has examined morphological changes in response to insularity and isolation, which has yielded useful generalizations about how animals can adapt to live in very small geographic areas. However, understanding the evolution of morphological variation in insular populations often requires detailed data sets on longitudinal patterns of growth and development, and such studies typically necessitate long-term mark-recapture on a large sample of individuals. Rattlesnakes provide a unique opportunity to address some of these difficulties because the addition of rattle segments to the rattle string occurs with regular periodicity and their size directly correlates with the body size of the snake at the time of the ecdysis cycle generating the segment. Here, we used a large database of rattle segment sizes recorded from island (Isla Coronado Sur, Baja California, Mexico) and mainland (Camp Pendleton, California, United States) populations of Western Rattlesnakes (Crotalus oreganus and C. o. caliginis) that separated approximately 10,000 years ago to compare body sizes at different ecdysis cycles, which allowed us to assess differences in growth rates and patterns of sexual size dimorphism. Our results show that rattlesnakes on Isla Coronado Sur appear to be born smaller and grow more slowly than their mainland counterparts, resulting in a "dwarfed" island population. However, despite significant differences in body size, both populations exhibited the same degree of sexual dimorphism. Our study demonstrates the potential to use rattle characteristics to recover detailed estimates of fundamental demographic parameters.

Natural history study of Pseudoachondroplasia: A focus on oral health.

BACKGROUND: Pseudoachondroplasia (PSACH) is a rare dwarfing condition characterized by short limbs and fingers, and multiple skeletal abnormalities/complications. There are few natural history studies delineating the medical problems in PSACH leaving a gap in many areas, especially oral health. Our study aimed to obtain information pertaining to oral health and other health-related problems (pregnancy and childbirth, skeletal health, joint pain) in patients with PSACH. METHODS: To ascertain this information, an online Qualtrics survey was distributed to members of Little People of America, a support group, and through a PSACH online chatroom. RESULTS: Ninety-nine of 115 surveys were completed and included in the descriptive and multivariable analyses. PSACH individuals regularly sought dental care, but flossing was challenging because of short fingers. Untreated carries (5%), bleeding gums (16%) malocclusion (37%), obstructive sleep apnea (9%), and TMJ disorder (3%) occurred less frequently compared to the general population. Delivery was by Caesarean section in 100% of female respondents who delivered a baby. Bowlegs (74%), scoliosis (43%) and osteoarthritis (36%) were the most common skeletal complications. Joint pain was reported by 85% of respondents. CONCLUSIONS: This study provides novel insights into oral health, pregnancy and childbirth while confirming previously identified skeletal complications in PSACH. Our findings suggest that oral healthcare in PSACH presents unique challenges.

Evidence for and against manganese deficiency as causal for congenital joint deficiency disease or death in fetal and neonatal cattle.

Measures of manganese (Mn) status in cattle vary among studies, and no single criterion accurately predicts or diagnoses Mn deficiency and pathologic outcomes. Mn deficiency causes congenital joint laxity and dwarfism (CJLD) when total dietary intake is <20 ppm Mn dry matter (DM) for most of the pregnancy. However, the recommended dietary intake of 40 ppm DM can also result in clinical Mn deficiency. Some studies have found that CJLD occurs in calves from cows fed red clover or silage but not in calves from cows fed hay. The concentration of Mn in the liver is the best indicator of Mn status in neonates and adults but cannot be interpreted in fetuses. Serum, plasma, and whole blood concentrations of Mn are unreliable indicators of bovine Mn status. The primary objective of our report is to present evidence linking CJLD to a primary or secondary Mn deficiency. To predict and diagnose Mn deficiency in cattle, we propose using a combination of clinical signs, dietary Mn, liver Mn at birth and beyond, positive response to Mn supplementation or the replacement of silage with other forages, and ruling out other causes of malformations. By following these recommendations, we expect that CJLD and gestational death will decrease as hepatic Mn concentrations increase at birth. Many publications we reviewed are not statistically sound, and future research should include a statistician from the initial discussions of the study through the final publication.

B-cell immune deficiency in twin sisters expands the phenotype of MOPDI.

Microcephalic osteodysplastic primordial dwarfism type I (MOPDI) is a very rare and severe autosomal recessive disorder characterized by marked intrauterine growth retardation, skeletal dysplasia, microcephaly and brain malformations. MOPDI is caused by biallelic mutations in RNU4ATAC, a non-coding gene involved in U12-type splicing of 1% of the introns in the genome, which are recognized by their specific splicing consensus sequences. Here, we describe a unique observation of immunodeficiency in twin sisters with mild MOPDI, who harbor a novel n.108_126del mutation, encompassing part of the U4atac snRNA 3' stem-loop and Sm protein binding site, and the previously reported n.111G>A mutation. Interestingly, both twin sisters show mild B-cell anomalies, including low naive B-cell counts and increased memory B-cell and plasmablasts counts, suggesting partial and transitory blockage of B-cell maturation and/or excessive activation of naive B-cells. Hence, the localization of a mutation in stem II of U4atac snRNA, as observed in another RNU4ATAC-opathy with immunodeficiency, that is, Roifman syndrome (RFMN), is not required for the occurrence of an immune deficiency. Finally, we emphasize the importance of considering immunodeficiency in MOPDI management to reduce the risk of serious infectious episodes.

Variable Syndromic Immunodeficiency in Patients with Biallelic PRIM1 Mutations.

Mutations in genes of the DNA polymerase complex have been linked to impaired immunological function next to distinct syndromic features. Biallelic mutations in PRIM1 are associated with a primordial dwarfism syndrome with variable hypogammaglobulinemia. The disease is mostly lethal in infancy due to pulmonary infections as well as hepatic cirrhosis. We studied 3 novel patients with PRIM1-deficiency with a focus on immunological consequences. All three shared dysmorphic features including a prominent forehead, triangular face and bilateral cryptorchidism. P1 carried the novel homozygous PRIM1 splice variant c.103+2T>G, allowing residual protein expression and associated with a mild clinical phenotype. P2 and P3 carried the known homozygous variant c.638+36C>G and died in infancy. Paradoxically, B cell lymphopenia was most pronounced in P1. No other significant lymphocyte abnormalities were detected. Interestingly, all 3 patients showed variable, but intermittently excessive Type I interferon signatures. In summary, the B-cell deficiency in PRIM1-deficiency is markedly variable and the severity of syndromic manifestations is not predictive of the immunological phenotype. We highlight a potential contribution of pathological type I interferon activation to disease pathogenesis which warrants further investigations.

Short beak and dwarfism syndrome among Pekin ducks: First detection, full genome sequencing, and immunohistochemical signals of novel goose parvovirus in tongue tissue.

Novel goose parvovirus (NGPV) is continuously threatening the global duck industry, as it causes short beak and dwarfism syndrome among different duck breeds. In this study, we investigated the viral pathogenesis in the tongue of affected ducks, as a new approach for deeper understanding of the syndrome. Seventy-three, 14- to 60-day-old commercial Pekin ducks were clinically examined. Thirty tissue pools of intestine and tongue (15 per tissue) were submitted for molecular identification. Clinical signs in the examined ducks were suggestive of parvovirus infection. All examined ducks had short beaks. Necrotic, swollen, and congested protruding tongues were recorded in adult ducks (37/73, 51%). Tongue protrusion without any marked congestion or swelling was observed in 20-day-old ducklings (13/73, 18%), and no tongue protrusion was observed in 15-day-old ducklings (23/73, 32%). Microscopically, the protruding tongues of adult ducks showed necrosis of the superficial epithelial layer with vacuolar degeneration. Glossitis was present in the nonprotruding tongues of young ducks, which was characterized by multifocal lymphoplasmacytic aggregates and edema in the propria submucosa. Immunohistochemical examination displayed parvovirus immunolabeling, mainly in the tongue propria submucosa. Based on polymerase chain reaction, goose parvovirus was detected in 9 out of 15 tongue sample pools (60%). Next-generation sequencing confirmed the presence of a variant goose parvovirus that is globally named NGPV and closely related to Chinese NGPV isolates. Novel insights are being gained from the study of NGPV pathogenesis in the tongue based on molecular and immunohistochemical identification.

Arterial stroke in a child with Seckel syndrome with a pattern of non-moyamoya vasculopathy.

Seckel syndrome is a rare autosomal recessive disorder, characterized by growth retardation and multiple anomalies associated with CNS vasculopathy. We describe a child with Seckel syndrome who developed a stroke due to non-moyamoya vasculopathy.

Genome cloning and genetic evolution analysis of eight duck-sourced novel goose parvovirus strains in China in 2023.

Introduction: There are three major categories of waterfowl parvoviruses, namely goose parvovirus (GPV), Muscovy duck parvovirus, and novel goose parvovirus (NGPV). NGPV can infect both Cherry Valley ducks and mule ducks, resulting in short beaks and dwarfism syndrome, and the incidence of short beaks and dwarfism syndrome rises annually, posing a significant threat to the waterfowl breeding and the animal husbandry. Therefore, clarifying the biological characteristics and genetic evolution of NGPV is very important for the prevention and control of NGPV. Methods: Ducks with short beaks and dwarfism syndrome from Shandong and Henan Province were investigated by dissection and the tissue samples were collected for study. The NGPV genome was amplified by PCR, and the genome was analyzed for genetic evolution. Results: Eight strains of NGPV were isolated, which were designated as HZ0512, HZ0527, HZ0714, HZ0723, HZ0726, HZ0811, HZ0815, and HN0403. The nucleotide homology among these strains ranged from 99.9% to 100%. The eight strains, along with other NGPVs, belong to GPV. The eight strains showed a 92.5%-98.9% nucleotide homology with the classical GPV, while a 96.0%-99.9% homology with NGPV.Therefore, it can be deduced that there have been no major mutations of NGPV in Shandong and Henan provinces in recent years. Discussion: This study lays a theoretical foundation for further studying the genetic evolution and pathogenicity of NGPV, thereby facilitating the prevention and control of NGPV.

Functional studies in yeast confirm the pathogenicity of a new GINS3 Meier-Gorlin syndrome variant.

Meier-Gorlin syndrome (MGORS) is an autosomal recessive disorder characterized by short stature, microtia, and patellar hypoplasia, and is caused by pathogenic variants of cellular factors involved in the initiation of DNA replication. We previously reported that biallelic variants in GINS3 leading to amino acid changes at position 24 (p.Asp24) cause MGORS. Here, we describe the phenotype of a new individual homozygous for the Asp24Asn variant. We also report the clinical characteristics of an individual harboring a novel homozygous GINS3 variant (Ile25Phe) and features suggestive of MGORS. Modification of the corresponding residue in yeast Psf3 (Val9Phe) compromised S phase progression compared to a humanized Psf3 Val9Ile variant. Expression of Psf3 Val9Phe in yeast also caused sensitivity to elevated temperature and the replicative stress-inducing drug hydroxyurea, confirming partial loss of function of this variant in vivo and allowing us to upgrade the classification of this variant. Taken together, these data validate the critical importance of the GINS DNA replication complex in the molecular etiology of MGORS.

Mutation of the Thap4 gene causes dwarfism and testicular anomalies in rats and mice.

The petit (pet) locus is associated with dwarfism, testicular anomalies, severe thymic hypoplasia, and high postnatal lethality, which are inherited in autosomal recessive mode of inheritance in rats with a Wistar strain genetic background. Linkage analysis localized the pet locus between 98.7 Mb and 101.2 Mb on rat chromosome 9. Nucleotide sequence analysis identified 2 bp deletion in exon 2 of the Thap4 gene as the causative mutation for pet. This deletion causes a frameshift and premature termination codon, resulting in a truncated THAP4 protein lacking approximately two-thirds of the C-terminal side. Thap4 is expressed in various organs, including the testis and thymus in rats. To elucidate the biological function of THAP4 in other species, we generated Thap4 knockout mice lacking exon 2 of the Thap4 gene through genome editing. Thap4 knockout mice also exhibited dwarfism and small testis but did not show high postnatal lethality. Thymus weights of adult Thap4 knockout male mice were significantly higher compared to wild-type male mice. Although Thap4 knockout male mice were fertile, their testis contained seminiferous tubules with spermatogenesis and degenerative seminiferous tubules lacking germ cells. Additionally, we observed vacuoles in seminiferous tubules, and clusters of cells in the lumen in seminiferous tubules in Thap4 knockout male mice. These results demonstrate that spontaneous mutation of Thap4 gene in rats and knockout of Thap4 gene in mice both cause dwarfism and testicular anomalies. Thap4 gene in rats and mice is essential for normal testicular development, maintaining spermatogenesis throughout the entire region of seminiferous tubules.

Postembryonic development and male paedomorphosis in Osedax (Siboglinidae, Annelida).

Most species of the bone-devouring marine annelid, Osedax, display distinct sexual dimorphism with macroscopic sedentary females rooted in bones and free-living microscopic dwarf males. The paedomorphic male resembles the non-feeding metatrochophore larva in size, presence of eight pairs of chaetae, and a head ciliation potentially representing a residual prototroch. The male development may thus uniquely reiterate and validate the theoretical heterochrony process "progenesis", which suggests that an accelerated sexual maturation and early arrest of somatic growth can lead to a miniaturized and paedomorphic adult. In this study, we describe the postembryonic larval and juvenile organogenesis of Osedax japonicus to test for a potential synchronous arrest of somatic growth during male development. Five postembryonic stages could be distinguished, resembling day one to five in the larval development at 10°C: (0D) first cleavage of fertilized eggs (embryos undergo unequal spiral cleavage), (1D) pre-trochophore, with apical organ, (2D) early trochophore, + prototroch, brain, circumesophageal connectives and subesophageal commissure, (3D) trochophore, + telotroch, four ventral nerves, (4D) early metatrochophore, + protonephridia, dorsal and terminal sensory organs, (5D) metatrochophore, + two ventral paratrochs, mid-ventral nerve, posterior trunk commissure, two dorsal nerves; competent for metamorphosis. The larval development largely mirrors that of other lecithotrophic annelid larvae but does not show continuous chaetogenesis or full gut development. Additionally, O. japonicus larvae exhibit an unpaired, mid-dorsal, sensory organ. Female individuals shed their larval traits during metamorphosis and continue organogenesis (including circulatory system) and extensive growth for 2-3 weeks before developing oocytes. In contrast, males develop sperm within a day of metamorphosis and display a synchronous metamorphic arrest in neural and muscular development, retaining a large portion of larval features post metamorphosis. Our findings hereby substantiate male miniaturization in Osedax to be the outcome of an early and synchronous offset of somatic development, fitting the theoretical process "progenesis". This may be the first compelling morpho-developmental exemplification of a progenetic origin of a microscopic body plan. The presented morphological staging system will further serve as a framework for future examination of molecular patterns and pathways determining Osedax development.

Cloning and functional mechanism of the dwarf gene gba affecting stem elongation and cellulose biosynthesis in jute (Corchorus olitorius).

Plant height (PH) is an important factor affecting bast fiber yield in jute. Here, we report the mechanism of dwarfism in the 'Guangbaai' (gba) of jute. The mutant gba had shorter internode length and cell length compared to the standard cultivar 'TaiZi 4' (TZ4). Exogenous GA3 treatment indicated that gba is a GA-insensitive dwarf mutant. Quantitative trait locus (QTL) analysis of three PH-related traits via a high-density genetic linkage map according to re-seq showed that a total of 25 QTLs were identified, including 13 QTLs for PH, with phenotypic variation explained ranging from 2.42 to 74.16%. Notably, the functional mechanism of the candidate gene CoGID1a, the gibberellic acid receptor, of the major locus qPHIL5 was evaluated by transgenic analysis and virus-induced gene silencing. A dwarf phenotype-related single nucleotide mutation in CoGID1a was identified in gba, which was also unique to the dwarf phenotype of gba among 57 cultivars. Cogid1a was unable to interact with the growth-repressor DELLA even in the presence of highly accumulated gibberellins in gba. Differentially expressed genes between transcriptomes of gba and TZ4 after GA3 treatment indicated up-regulation of genes involved in gibberellin and cellulose synthesis in gba. Interestingly, it was found that up-regulation of CoMYB46, a key transcription factor in the secondary cell wall, by the highly accumulated gibberellins in gba promoted the expression of cellulose synthase genes CoCesA4 and CoCesA7. These findings provide valuable insights into fiber development affected by endogenous gibberellin accumulation in plants.

Genetic evaluation using next-generation sequencing of children with short stature: a single tertiary-center experience.

PURPOSE: We used next-generation sequencing (NGS) to investigate the genetic causes of suspected genetic short stature in 37 patients, and we describe their phenotypes and various genetic spectra. METHODS: We reviewed the medical records of 50 patients who underwent genetic testing using NGS for suspected genetic short stature from June 2019 to December 2022. Patients with short stature caused by nongenetic factors or common chromosomal abnormalities were excluded. Thirty-seven patients from 35 families were enrolled in this study. We administered one of three genetic tests (2 targeted panel tests or whole exome sequencing) to patients according to their phenotypes. RESULTS: Clinical and molecular diagnoses were confirmed in 15 of the 37 patients, for an overall diagnostic yield of 40.5%. Fifteen pathogenic/likely pathogenic variants were identified in 13 genes (ACAN, ANKRD11, ARID1B, CEP152, COL10A1, COL1A2, EXT1, FGFR3, NIPBL, NRAS, PTPN11, SHOX, SLC16A2). The diagnostic rate was highest in patients who were small for their gestational age (7 of 11, 63.6%). CONCLUSION: Genetic evaluation using NGS can be helpful in patients with suspected genetic short stature who have clinical and genetic heterogeneity. Further studies are needed to develop patient selection algorithms and panels containing growth-related genes.

Curcumin and Resveratrol: Nutraceuticals with so Much Potential for Pseudoachondroplasia and Other ER-Stress Conditions.

Natural products with health benefits, nutraceuticals, have shown considerable promise in many studies; however, this potential has yet to translate into widespread clinical use for any condition. Notably, many drugs currently on the market, including the first analgesic aspirin, are derived from plant extracts, emphasizing the historical significance of natural products in drug development. Curcumin and resveratrol, well-studied nutraceuticals, have excellent safety profiles with relatively mild side effects. Their long history of safe use and the natural origins of numerous drugs contrast with the unfavorable reputation associated with nutraceuticals. This review aims to explore the nutraceutical potential for treating pseudoachondroplasia, a rare dwarfing condition, by relating the mechanisms of action of curcumin and resveratrol to molecular pathology. Specifically, we will examine the curcumin and resveratrol mechanisms of action related to endoplasmic reticulum stress, inflammation, oxidative stress, cartilage health, and pain. Additionally, the barriers to the effective use of nutraceuticals will be discussed. These challenges include poor bioavailability, variations in content and purity that lead to inconsistent results in clinical trials, as well as prevailing perceptions among both the public and medical professionals. Addressing these hurdles is crucial to realizing the full therapeutic potential of nutraceuticals in the context of pseudoachondroplasia and other health conditions that might benefit.

Unlocking the Enigma: Investigating I-Cell Disease in a Newborn Through Placental Pathology.

I-cell disease (Mucolipidosis Type II) is a rare lysosomal storage disorder caused by GNPTAB gene defects, leading to severe morbidity and mortality. The authors present the case of a neonate born at 38 wk gestational age, with suspected skeletal dysplasia during pregnancy and a complex clinical and laboratory presentation after birth. This is a rare case, and its diagnosis was made through placental pathology, which revealed the condition called mucolipidosis Type II. To the best of authors' knowledge, this is one of the few cases diagnosed in the neonatal period with placental pathology globally and the first in Canada, highlighting the significance of placental pathology for the diagnosis of these rare conditions and future counseling of the parents. In conclusion, mucolipidosis Type II is a rare condition in neonates. Early diagnosis in neonates can be made through placental pathology for parental counseling.

Mutational analysis of consanguineous families and their targeted therapy against dwarfism.

Dwarfism is a medical term used to describe individuals with a height-vertex measurement that falls below two standard deviations (-2SD) or the third percentile for their gender and age. Normal development of growth is a complicated dynamic procedure that depends upon the coordination of different aspects involving diet, genetics, and biological aspects like hormones in equilibrium. Any severe or acute pathologic procedure may disturb the individual's normal rate of growth. In this research, we examined four (A-D) Pakistani consanguineous families that exhibited syndromic dwarfism, which was inherited in an autosomal recessive pattern. The genomic DNA of each family member was extracted by using phenol-chloroform and Kit methods. Whole Exome Sequencing (WES) of affected family members (IV-11, III-5, IV-4 and III-13) from each group was performed at the Department of Medical Genetics, University of Antwerp, Belgium. After filtering the exome data, the mutations in PPM1F, FGFR3, ERCC2, and PCNT genes were determined by Sanger sequencing of each gene by using specific primers. Afterward, FGFR3 was found to be a suitable drug target among all the mutations to treat achondroplasia also known as disproportionate dwarfism. BioSolveIT softwares were used to discover the lead active inhibitory molecule against FGFR3. This research will not only provide short knowledge to the concerned pediatricians, researchers, and family physicians for the preliminary assessment and management of the disorder but also provide a lead inhibitor for the treatment of disproportionate dwarfism.Communicated by Ramaswamy H. Sarma.

Anesthetic management of parturients with achondroplasia: a case series.

Background: Achondroplasia is the most common form of dwarfism, and cesarean delivery is often required in parturients with achondroplasia due to cephalopelvic disproportion. Given the challenges for both regional and general anesthetic techniques, there is no consensus on the optimal anesthetic management for cesarean delivery in these patients. Method: A search of our electronic medical records for all female patients who had a diagnosis of achondroplasia and had a delivery in our health system from January 1, 2001 through June 16, 2023 was performed. Institutional review board exemption was obtained. Results: We identified seven achondroplastic patients with 12 cesarean deliveries and described their anesthetic management during labor and delivery. Conclusion: Despite the historical preference of general anesthesia in achondroplastic patients due to concerns of unpredictable spinal anatomy and unreliable local anesthetic spread, neuraxial anesthesia was successfully utilized in achondroplastic parturients and is a viable option in carefully selected patients. Reduction of intrathecal local anesthetic dose that minimizes the risk of high spinal and emergent intubation, as well as a titratable neuraxial technique, can be effective in this patient population.

Uncommon life history and winter spawning of common carp (Cyprinus carpio) in a natural thermal spring, under temperate climate.

Common carp female generally matures at age 4-5 years old and spawns between April and July under the temperate climate. Contrary to a range of 0-28 °C of temperate freshwaters, the water temperature of Lake Hévíz (Hungary, Central Europe), the largest natural bathable thermal lake in the world, varies between 26 and 35 °C seasonally. The specific environmental conditions (continuously warm water and its individual chemical composition, special nutrient base, lack of natural lakeside spawning substrate compared to usual spawning grounds, continuous high human disturbance, etc.) suggest that the carp population here may also differ in reproductive characteristics from their counterparts in surrounding waters. Our findings suggest that the self-sustaining dwarf common carp population of Lake Hévíz matures 2 to 4 years earlier (at the age of one) and spawns 1 to 3 months before (between February and April, at 27-30 °C water temperature) than carp typically do in the temperate zone (16-20 °C). Successful winter spawning was verified by rearing larvae from the collected eggs and in situ induced propagation.

Transcriptomic and Phenotypic Analyses Reveal the Molecular Mechanism of Dwarfing in Tetraploid Robinia pseudoacacia L.

Polyploid breeding techniques aid in the cultivation of new forestry cultivars, thus expanding the suite of strategies for the improvement of arboreal traits and innovation within the field of forestry. Compared to diploid Robinia pseudoacacia L. (black locust) 'D26-5①' (2×), its dwarfed homologous tetraploid 'D26-5②' (4×) variety has better application prospects in garden vegetation guardrails and urban landscape. However, the molecular mechanism of the generation and growth of this dwarf variety is still unclear. Here, plant growth and development as well as histological differences between the diploid and its autotetraploid were investigated. Levels of endogenous hormones at three different developmental stages (20, 40, and 70 days) of 2× and homologous 4× tissue culture plantlets were assessed, and it was found that the brassinosteroid (BR) contents of the former were significantly higher than the latter. Transcriptome sequencing data analysis of 2× and homologous 4× showed that differentially expressed genes (DEGs) were significantly enriched in plant hormone synthesis and signal transduction, sugar and starch metabolism, and the plant circadian rhythm pathway, which are closely related to plant growth and development. Therefore, these biological pathways may be important regulatory pathways leading to dwarfism and slow growth in tetraploids. Additionally, utilizing weighted gene coexpression network analysis (WGCNA), we identified three crucial differentially expressed genes (DEGs)-PRR5, CYP450, and SPA1-that potentially underlie the observed ploidy variation. This study provides a new reference for the molecular mechanism of dwarfism in dwarfed autotetraploid black locusts. Collectively, our results of metabolite analysis and comparative transcriptomics confirm that plant hormone signaling and the circadian rhythm pathway result in dwarfism in black locusts.