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At least 19 recordsLinked to original sources

A Deep Model Framework for Morphological Trait Imputation Across Taxonomic Groups.

Incomplete morphological trait data pose major hurdles for trait-based analyses, particularly when missing values, multicollinearity, and sparse sampling constrain inference. These issues limit our ability to quantify trait variation and explore broad patterns of functional differentiation across taxa. Here, we introduce FS-DeepRBFNet, which overcomes these pitfalls through integrating correlation-based feature selection with a dual-layer adaptive radial basis function (RBF) network. This end-to-end approach effectively reduces noise and captures both linear allometric trends and nonlinear morphological relationships. We tested the framework on a large species-level morphological trait dataset of Chinese birds and further validated its cross-taxon transferability using the Amphibian Database (Caudata). FS-DeepRBFNet consistently outperformed conventional methods such as KNN, Random Forest, and XGBoost, demonstrating superior predictive accuracy across multiple traits. Beyond improvements, the model revealed biologically interpretable trait associations and stable cross-taxon generalization. These results demonstrate that FS-DeepRBFNet provides a robust and biologically grounded solution for morphological trait prediction, enabling reliable imputation for comparative phylogenetics, functional ecology, and biodiversity forecasting in data-limited situations.

cross‐taxon transferability

Optimized phenotyping of complex morphological traits: enhancing discovery of common and rare genetic variants.

Genotype-phenotype (G-P) analyses for complex morphological traits typically utilize simple, predetermined anatomical measures or features derived via unsupervised dimension reduction techniques (e.g. principal component analysis (PCA) or eigen-shapes). Despite the popularity of these approaches, they do not necessarily reveal axes of phenotypic variation that are genetically relevant. Therefore, we introduce a framework to optimize phenotyping for G-P analyses, such as genome-wide association studies (GWAS) of common variants or rare variant association studies (RVAS) of rare variants. Our strategy is two-fold: (i) we construct a multidimensional feature space spanning a wide range of phenotypic variation, and (ii) within this feature space, we use an optimization algorithm to search for directions or feature combinations that are genetically enriched. To test our approach, we examine human facial shape in the context of GWAS and RVAS. In GWAS, we optimize for phenotypes exhibiting high heritability, estimated from either family data or genomic relatedness measured in unrelated individuals. In RVAS, we optimize for the skewness of phenotype distributions, aiming to detect commingled distributions that suggest single or few genomic loci with major effects. We compare our approach with eigen-shapes as baseline in GWAS involving 8246 individuals of European ancestry and in gene-based tests of rare variants with a subset of 1906 individuals. After applying linkage disequilibrium score regression to our GWAS results, heritability-enriched phenotypes yielded the highest SNP heritability, followed by eigen-shapes, while commingling-based traits displayed the lowest SNP heritability. Heritability-enriched phenotypes also exhibited higher discovery rates, identifying the same number of independent genomic loci as eigen-shapes with a smaller effective number of traits. For RVAS, commingling-based traits resulted in more genes passing the exome-wide significance threshold than eigen-shapes, while heritability-enriched phenotypes lead to only a few associations. Overall, our results demonstrate that optimized phenotyping allows for the extraction of genetically relevant traits that can specifically enhance discovery efforts of common and rare variants, as evidenced by their increased power in facial GWAS and RVAS.

Humans

Genomic prediction and genome-wide association studies of morphological traits and distraction index in Korean Sapsaree dogs.

The Korean Sapsaree dog is a native breed known for its distinctive appearance and historical significance in Korean culture. The accurate estimation of breeding values is essential for the genetic improvement and conservation of such indigenous breeds. This study aimed to evaluate the accuracy of breeding values for body height, body length, chest width, hair length, and distraction index (DI) traits in Korean Sapsaree dogs. Additionally, a genome-wide association study (GWAS) was conducted to identify the genomic regions and nearby candidate genes influencing these traits. Phenotypic data were collected from 378 Korean Sapsaree dogs, and of these, 234 individuals were genotyped using the 170k Illumina CanineHD BeadChip. The accuracy of genomic predictions was evaluated using the traditional BLUP method with phenotypes only on genotyped animals (PBLUP-G), another traditional BLUP method using a pedigree-based relationship matrix (PBLUP) for all individuals, a GBLUP method based on a genomic relationship matrix, and a single-step GBLUP (ssGBLUP) method. Heritability estimates for body height, body length, chest width, hair length, and DI were 0.45, 0.39, 0.32, 0.55, and 0.50, respectively. Accuracy values varied across methods, with ranges of 0.22 to 0.31 for PBLUP-G, 0.30 to 0.57 for PBLUP, 0.31 to 0.54 for GBLUP, and 0.39 to 0.67 for ssGBLUP. Through GWAS, 194 genome-wide significant SNPs associated with studied Sapsaree traits were identified. The selection of the most promising candidate genes was based on gene ontology (GO) terms and functions previously identified to influence traits. Notable genes included CCKAR and DCAF16 for body height, PDZRN3 and CNTN1 for body length, TRIM63, KDELR2, and SUPT3H for chest width, RSPO2, EIF3E, PKHD1L1, TRPS1, and EXT1 for hair length, and DDHD1, BMP4, SEMA3C, and FOXP1 for the DI. These findings suggest that significant QTL, combined with functional candidate genes, can be leveraged to improve the genetic quality of the Sapsaree population. This study provides a foundation for more effective breeding strategies aimed at preserving and enhancing the unique traits of this Korean dog breed.

Animals

[Diploid radiation-induced gynogenesis in carp. II. Segragation according to morphological traits in gynogenetic progenies].

The character of segregation in diploid gynogenetic progenies of Cyprinus carpio with respect to the following three external characters was studied: the type of scale cover, the colour and the design. The genetic formulae of these characters are as follows: the type of scale cover: scaled--(Snn); scattered--(ssnn); linear--(S--Nn); nude--(ssNn); the existence of design (D--); the absence of design--(dd); the type of colour: light--(LI); dark--(II). The dominant genes N and L exert a recessive lethal effect. For the loci N--n, D--d and L--l a conspicuous prevalence of dominant form was established. Linear and nude carps constituted 98%, light carps--85% and carps with a design--also 85% of the total number of gynogenetic descendants. The proportions of heterozygotes Nn, Ll and Dd were 97.3, 73.9 and 70.0% respectively. The frequencies of descendants dominant and recessive for the locus S--s proved to be closely similar: 52.4% (S--) and 47.6% (ss)the proportion of heterozygotes Ss being 4.8%. The data on the frequency of gynogenetic heterozygotes suggest the existence of a high positive interference in the carp. The value of the latter for the four loci studied, the genetic distance between each of these loci and "its" centromere was determined. The data obtained are discussed.

Animals

Tooth size associations of three morphologic dental traits in a melanesian population.

The tooth size associations of incisor shoveling, Carabelli's cusp, and mandibular molar groove pattern were determined for a technologically primitive Melanesian population. Their significance to previously postulated adaptive mechanisms for the morphologic traits is evaluated, as is a possible mode of inheritance for the traits.

Adolescent

Convergent evolution of gene expression in two high-toothed stickleback populations.

Changes in developmental gene regulatory networks enable evolved changes in morphology. These changes can be in cis regulatory elements that act in an allele-specific manner, or changes to the overall trans regulatory environment that interacts with cis regulatory sequences. Here we address several questions about the evolution of gene expression accompanying a convergently evolved constructive morphological trait, increases in tooth number in two independently derived freshwater populations of threespine stickleback fish (Gasterosteus aculeatus). Are convergently evolved cis and/or trans changes in gene expression associated with convergently evolved morphological evolution? Do cis or trans regulatory changes contribute more to gene expression changes accompanying an evolved morphological gain trait? Transcriptome data from dental tissue of ancestral low-toothed and two independently derived high-toothed stickleback populations revealed significantly shared gene expression changes that have convergently evolved in the two high-toothed populations. Comparing cis and trans regulatory changes using phased gene expression data from F1 hybrids, we found that trans regulatory changes were predominant and more likely to be shared among both high-toothed populations. In contrast, while cis regulatory changes have evolved in both high-toothed populations, overall these changes were distinct and not shared among high-toothed populations. Together these data suggest that a convergently evolved trait can occur through genetically distinct regulatory changes that converge on similar trans regulatory environments.

Alleles

Selection of geographical populations suitable for artificial breeding of the Northeast China Brown Frog (Rana dybowskii).

Amphibians, as a group greatly disturbed by human activities, are at increased risk of extinction. Rana dybowskii is an anuran species with both ecological and economic significance. Due to environmental changes and human overexploitation, it has been classified as Near-Threatened. This study integrates morphological and molecular immunological approaches to identify R. dybowskii populations with greater survival and disease resistance, based on 32 morphological traits and MHC class I and II polymorphism. Morphological results showed that compared with other populations, Yichun (YC) population had the highest fatness, the lowest IOD/HW, and the largest HW/SVL, HL/SVL, HW/HL, SL/TL. It indicates that YC population shows larger body size, wider vision and stronger jumping ability. The polymorphism of MHC I gene was the highest in Shangzhi (SZ) population, and the polymorphism of MHC II gene was the highest in YC population. Moreover, duplication, selection, and recombination occurred during evolution of MHC class I and II genes. Since both SZ and YC populations scored higher in this category (the variant sites, nucleotide polymorphism, amino-acid divergence/nucleotide divergence, dN/dS, Tajima' D, etc.), they were more resistant to disease. All in all, these results indicated that YC population of the Lesser Khingan Mountains had good morphology and immune results, and R. dybowskii in the Lesser Khingan Mountains might be more suitable to be the original population of artificial breeding, which provided a theoretical basis for the realization of artificial breeding in the next step.

Ranidae

Near-complete reference genome assembly of Hoya carnosa.

Hoya R. Br. is the largest genus in the tribe Marsdenieae (Apocynaceae), comprising 350-450 species. Hoya species are popular in horticulture for their distinctive floral traits and fragrances, primarily sourced from domestication and mutation breeding. However, the lack of molecular analysis for floral morphological traits has limited their cultivation and application. In this study, we assembled a near-complete reference genome for H. carnosa, the model species of the genus, using PacBio HiFi reads and Hi-C method. The genome size was approximately 465.7 Mb with a contig N50 of 39.3 Mb. 99.7% of the sequences were anchored to 11 pseudochromosomes, and the assembly achieved a BUSCO score of 98.5%. We predicted 24,309 protein-coding genes, of which 90.2% (21,927) were functionally annotated. This high-quality genome provides a valuable reference for the research of evolution, conservation and molecular breeding in Hoya.

Genome, Plant

Extensive Introgression Failed to Erode Species Boundaries Among Multiple Sympatric Closely Related Species of Roscoea.

How species boundaries are maintained among sympatric closely related species experiencing gene flow is a puzzling question in evolutionary biology. Although introgression is commonly documented, the dynamics and gene function of introgression have rarely been explored to probe why frequent introgression does not necessarily destroy species boundaries in sympatry. In this study, we employ whole-genome resequencing data to examine introgression among five closely related species of Roscoea that coexist in a 'sky island' with seventeen distinct morphological traits. Our findings reveal that introgression has led to the phylogenomic discordance between nuclear and chloroplast genomes among these morphologically distinct species. Additionally, introgression is predominantly asymmetrical in both intensity and gene function, particularly concerning recombination. Notably, the majority of gene functions associated with introgressed loci are unrelated to reproductive processes. Our results suggest that closely related species with incomplete allele assortment can coexist despite theoretical predictions, highlighting the semipermeable nature of species boundaries as reproductive isolation develops. This provides a critical conceptual framework for understanding the interplay between introgression and species persistence. Our finding offers insights into how related sympatric species boundaries can be maintained in the face of frequent asymmetrical gene introgression.

Sympatry

Dental condition of two tribes of Taiwan aborigines--Ami and Atayal.

This is a study of dental and oral conditions of Taiwan aborigines from the epidemiological and anthropological points of view. A total of 166 Ami and 128 Atayal adolescents were included from their original living area, the Hwa-Lien Hsin and Wa-Lai District, Taiwan, Republic of China. Oral examination was done carefully and caries incidence, periodontal index, and Angle's Classification combined with OFI were included. After that, hydrocolloid impressions were taken, and dental casts were immediately made. The mesiodistal and buccloingual crown diameters and also the arch depth and width were measured using a sliding caliper. Dental morphological traits, such as shovel-shaped incisors, Carabelli's cusp, protostylid, and upper and lower molar groove patterns were observed and classified, and the results are given with statistical analysis. The aborigines have a quite low incidence of dental caries and periodontal disease which may be related to their dietary habits, good oral hygiene, and good dental occlusion. With regard to the differences between the Ami and Atayal, most of the date show no statistical significance except in the dental occlusion. The Atayal's occlusion is better than that of the differences of genetics or other factors. There are no sex differences in all the date in the dental survey, but there are sex differences in both the misiodistal and buccolingual crown diameters of both the Ami and Atayal tribes (the tooth crown of the male subjects is invariably broader and larger than that of females). In the dental arch dimensions, most of the data show no sex diffreence, except in the breadth of the upper and lower dental arch of the Atayal. Anthropologically, there are no statistical differences, in mesiodistal and buccolingual crown diameters and most of the data of dental arch dimesions, but there is a difference in arch depth in Ami and Atayal adolescents. The Atayal have a deeper dental arch than do the Ami. As for dental morphologi, the Taiwan aborigines have a high frequency of shovel-shaped incisors and Carabelli's trait but a relatively low frequency of protostylid. There are no definite differences between races in the occlusal pattern of maxillary first molars, but there are differences in the maxillary second molars. The usual pattern is 4-- for the upper first and second molars of the Taiwan aborigines as well as for thedibular occlusal pattern, the first molar tends to follow the primitive "dryopithecus" pattern of 5 cusps and Y configuration, but in the second molar there are varying degrees of departure from Y5 to the more advanced +4 pattern with +5 and Y4 as intermediates.

Adolescent

Genetic structure of a tribal population, the Yanomama Indians. XIII. Dental microdifferentiation.

Data are presented on the frequency of the following eight dental traits in 635 Yanomama and 65 Makiritare Indians: upper central incisor rotation or winging, shoveling of maxillary incisors, maxillary molar hypocone reduction, Carabelli's trait, mandibular molar cusp number, mandibular molar cusp pattern rotation of second lower premolar, and pattern of second lower premolar cusps. Yanomama dentition is unusual in the high frequency of six cusps on the mandibular molars. There is marked dental microdifferentiation between villages; significant agreement was observed between a matrix of pairwise "dental distances" based on six morphological traits and corresponding matrices based on 11 genetic systems and on geographic location.

Brazil

Long-time survival and morphological stability of preserved Sporothrix schenckii strains.

The survival and stability of morphological traits of 33 Sporothrix schenckii strains were evaluated. Strain subcultures were maintained under mineral oil for different periods of time lasting as long as 41 years, or in sterile distilled water for as long as 23 years. Of the 33 strains preserved under mineral oil, 28 (85%) maintained viability and unchanged macro- and microscopic characteristics. All of the 4 strains maintained in distilled water also remained viable, with no morphological changes. The results confirm the efficiency of the methods used to preserve strains of the pathogenous and anamorphous fungus Sp. schenckii, especially in laboratories of limited resources.

Microbiological Techniques

The lorisiform wrist joint and the evolution of "brachiating" adaptations in the hominoidea.

In lorisines (Loris, Nycticebus, Perodicticus, Arctocebus), the tip of the ulna is reduced to the dimensions of a styloid process, a new and more proximal ulnar head is developed, and the pisiform is displaced distally away from its primitive contact with the ulna. In some Nycticebus, intra-articular tissues separate the ulna from the triquetrum. These traits are not seen in other quadrupedal primates, but they are characteristic of extant hominoids. Among hominoids, these features have been interpreted as adaptations to arm-swinging locomotion. Since hominoid-like features of the wrist joint are found in lorisines, but not in New World monkeys that practice arm-swinging locomotion, these features may have been evolved in both lorisines and large hominoids to enhance wrist mobility for cautious arboreal locomotion involving little or no leaping. Most of the other morphological traits characteristic of modern hominoids can be explained as adaptations to cautious quadrupedalism as well as to brachiation, and may have developed for different reasons in different lineages descended from an unspecialized cautious quadruped resembling Alouatta.

Animals

Morphological changes and transcriptomic insights into skeletal development of embryos and larvae of the sea urchin Strongylocentrotus intermedius.

To explore morphological features and molecular dynamics underlying skeletogenesis in the sea urchin Strongylocentrotus intermedius, we conducted combined morphological observation and comparative transcriptome analyses across representative embryonic and larval developmental stages. Morphological results showed that triradiate spicules first emerged at the gastrula stage. The 8-arm pluteus stage was identified as a key phase for skeletal remodeling, during which new three-radiate crystals transformed into complex stereoscopic ossicles including tube feet, spines and test plates. Transcriptomic data indicated that most differentially expressed genes (DEGs) were downregulated from the blastula to gastrula. The altered expression of basal metabolic genes and extracellular matrix genes including Colp2α and calm may be correlated with the linear mineralization of early spicules, which potentially reflects an energy adjustment pattern in developing larvae. During the transition from 6-arm to 8-arm pluteus, expression changes of calmodulin-like, Colp2α and SISin18G001660 suggest potential associations with regional calcium deposition and modifications of skeletal matrix properties. This work systematically characterizes morphological traits and transcriptional dynamics of skeletogenesis in S. intermedius. Its early spiculogenesis follows the conserved developmental pattern of echinoderms, while massive formation of stereoscopic ossicles occurs at the 8-arm pluteus stage. Stage-specific transcriptional changes across key larval skeletogenic stages are uncovered, offering transcriptomic resources for functional verification of skeletal regulatory genes.

Animals

Single-cell profiling decodes patagium development in gliding mammal.

The gliding patagium represents a key adaptation for mammalian flight, but its cellular development remains unexplored. Using single-nucleus RNA sequencing of embryonic flying squirrel patagium and dorsal skin, we construct a single-cell atlas of patagium development and identify two distinct fibroblast subpopulations (Fp2 and Fr) highly enriched in the patagium. These fibroblasts are characterized by the patagium upregulation of Wnt5a, Fgf7, and Fgf10, and are associated with patagium morphogenesis through dermal-epidermal putative communication interactions between dermal fibroblasts (Fp2 and Fr) and epithelial basal keratinocytes. Specifically, Fp2 fibroblasts are potentially involved in distal dermal condensation and epithelial thickening together with elevated Wnt5a expression, while both Fp2 and Fr fibroblasts could play a role in epithelial polarization and thickening through Fgf7 and Fgf10, as suggested by ex vivo assays. Our data suggest that gliding patagium development results from the co-option of conserved WNT and FGF signaling pathways within a specialized fibroblast-epithelial context, illustrating how modifications of conserved developmental programs give rise to derived morphological traits.

Animals

Cis-regulatory evolution of Wnt-family genes contributes to a morphological difference between silkworm species.

Closely related species often exhibit distinct morphologies that can contribute to species-specific adaptations and reproductive isolation. One example are Lepidopteran caterpillar appendages, such as the "caudal horn" of Bombycoidea moths, which have evolved substantial morphological diversity among species in this group. Using interspecific crosses, we identify the genetic basis of the caudal horn size difference between Bombyx mori and its closest relative B. mandarina. The three largest of eight QTL account for one third the mean horn length difference between the species. The largest of these, on chromosome 4, encompasses a conserved Wnt-family gene cluster, key upstream regulators that are well-known for their roles in morphological diversification in animals. Using allele-specific expression analysis and CRISPR/Cas9 knockouts, we show that tissue-specific cis-regulatory changes to Wnt1 and Wnt6 contribute to the species difference in caudal horn size. This kind of modularity enables highly pleiotropic genes, including key upstream growth regulators, to contribute to the evolution of morphological traits without causing widespread deleterious effects.

Journal Article

An epidemiologic study of occlusal anomalies in relation to development of the dentition in Icelandic children.

The purpose of the investigation was to determine the prevalence of occlusal anomalies in relation to dental stages (DS) in Icelandic schoolchildren, and to compare it with results from other Scandinavian countries and Ireland found on the basis of the same method. The material consisted of 1,641 randomly selected children, 791 boys and 850 girls, corresponding to 9.5% of the total primary and secondary school population of Reykjavík. A significant sex difference was only recorded in the frequencies of of two of the single morphologic traits of occlusal anomalies, the boys showing higher frequencies in deep bite and in scissors-bite. Significant differences in the occurrence of occlusal anomalies in Iceland and Denmark were only found in two out of 108 pairs of frequencies.

Child