Dorsal Stripe Research Articles

Oligodon cicadophagus, a new kukri snake from southern peninsular Thailand (Squamata: Colubridae)

We describe a new kukri snake, Oligodon cicadophagus sp. nov., from the limestone reliefs of the Phuket Mountain Range in Krabi and Phang-Nga provinces in southern peninsular Thailand. A member of the Oligodon cinereus group, it can be distinguished from all other congeneric species by the combination of its maximal known snout-vent length of 537 mm; 11 maxillary teeth; eight supralabials; one preocular and one presubocular; 17-17-15 dorsal scale rows; 159–168 ventrals, and 50 subcaudals in males; a single anal scale; hemipenes bilobed with large broad lobes, no distinct flounced calyces and unforked sulcus spermaticus; dorsal surface of head, body and tail uniformly olive-gray, without nuchal chevron, dorsal stripes, crossbands, blotches or reticulations; and a venter cream anteriorly turning to dark gray posteriorly.

Uroderma magnirostrum (Chiroptera: Phyllostomidae)

Abstract Uroderma magnirostrum Davis, 1968, the Brown Tent-making Bat, is a medium-sized frugivorous phyllostomid. It is characterized by poorly defined facial and dorsal stripes, large bifid upper inner incisors, and a laterally expanded mesethmoid bone. Uroderma magnirostrum is widely distributed between western Mexico and southeastern Brazil, and across its distribution, it inhabits different types of environments (e.g., pristine tropical forests; farmlands; mangroves; savannas; urban green areas). It is listed as “Least Concern” (LC) by the International Union for Conservation of Nature and Natural Resources but appears in national red lists, such as those from Guatemala and Nicaragua, due to the significant impact of the human activities in these countries.

Pigmentation polymorphism of <i>Dikerogammarus villosus</i> (Amphipoda, Crustacea) from the Kuban River, Caucasus

The purpose of this work was to determine the number of morphs and their ratio in the population of Dikerogammarus villosus from the Kuban River, as well as to establish color indicators and the total number of hemocytes in each morph. Amphipods were caught for study in the vicinity of the city of Krasnodar at the confluence of Lake Staraya Kuban with the Kuban River in 2023 and 2024. The analysis of color indicators was carried out using Adobe Photoshop (CIELab) and GIMP software. The total number of hemocytes was determined after the acclimation of individuals to laboratory conditions, which was performed for three days. In the Kuban River, D. villosus was found to be characterized by 4 types of pigment distribution: spotted or patterned (S), homogeneous pigmentation – melanin (M), with dorsal stripes (B) and amber (A). Based on this, we identified four morphs. At the same time, in the morphs with dorsal stripes, we identified two sub–morphs: B1 with wide pigment stripes along the entire pereon, and B2 with thin pigment stripes. The ratio (%) of morphs was as follows: B – 72.1, S – 16.0, M – 7.7, A – 3.3, and T – 0.9. There were no differences in color indices between the morphs, but statistically significant differences were found between morph M and the other morphs in color brightness, the melanin morph was 1.5 times darker as compared to morphs B and S (p 0.005). The total number of D. villosus hemocytes widely ranged from 2480 to 9020 pcs/ml, averaging 4858 ± 1684 pcs/ml. No correlations between the size of individuals and the number of hemocytes were established (p 0.05). There were also no differences in the number of hemocytes between males and females (p 0.05). Hematological variations between the five morphs were not statistically significant either (p = 0.36). Thus, for the first time, the ratio of amphipod morphs of the species D. villosus from the plain part of the lower reaches of Kuban River was determined. Data on the color indices of morphs and the total number of hemocytes of this species are presented.

Paracapillaria (Ophidiocapillaria) siamensis sp. nov. (Nematoda: Trichuroidea): a new nematode in Naja kaouthia from Thailand.

A comprehensive investigation, incorporating both morphological and molecular analyses, has unveiled the existence of a hitherto unknown nematode species, Paracapillaria (Ophidiocapillaria) siamensis sp. nov., residing in the intestine of the monocled cobra, Naja kaouthia, in the central region of Thailand. This study integrates morphological characteristics, morphometric examination, scanning electron microscopy and molecular phylogenetic analysis (COI, 18S rRNA and ITS1 genes). The findings place the newly described species within the subgenus Ophidiocapillaria, elucidating its distinctive characteristics, including a frame-like proximal spicule shape, approximate lengths of 19 000 and 22 500 μm with approximate widths of 90 and 130 μm for males and females, 39‒45 stichocytes, elevated lips without protrusion, a dorsal bacillary band stripe with an irregular pattern of bacillary cells and evidence of intestinal infection. These features serve to differentiate it from other species within the same subgenus, notably Paracapillaria (Ophidiocapillaria) najae De, , a species coexisting P. siamensis sp. nov. in the monocled cobra from the same locality. This study addresses the co-infection of the novel species and P. najae within the same snake host, marking the second documented instance of a paracapillariid species in the monocled cobra within the family Elapidae. The genetic characterization supports the formal recognition of P. siamensis sp. nov. as a distinct species, thereby underscoring its taxonomic differentiation within the Capillariidae family. This research identifies and characterizes the new nematode species, contributing valuable insights into the taxonomy of this nematode.

Caracterização morfológica, craniodental e molecular de Platyrrhinus guianensis (Chiroptera, Phyllostomidae) e segundo registro para o Brasil

ABSTRACT The genus Platyrrhinus Saussure, 1860 is one of the most speciose within the Phyllostomidae family in the Neotropical region, with 19 documented species worldwide, nine of which are found in Brazil. Platyrrhinus guianensis Velazco and Lim, 2014 was first recorded in the Guiana Shield, followed by a record in the Brazilian Amazon. This study represents the second record of P. guianensis in Brazil, specifically in the Maranhão (MA) Amazon biome (Turiaçu/MA - 01°39’36”S and 45°22’12”W). Morphological, craniodental, and molecular characters were employed for species identification. The specimen exhibited a dark brown dorsal fur, a conspicuous wide and white dorsal stripe, dark gray ventral fur, a forearm length of 38.5 mm, a short skull without a fossa in the scaly root of the zygomatic arch, with two stylar cusps on the posterior crest of the upper second premolar, one stylar cusp on the anterior crest of the lower second premolar, and upper internal incisors bilobed and convergent. Molecular results supported the morphological identification, confirming the occurrence of P. guianensis in the Maranhão Amazon. Molecular results provide the first public sequence of P. guianensis for the 16S rRNA gene and a new sequence for the COI gene, which will be useful in future studies for the species. These results supported the morphological identification, confirming the occurrence of P. guianensis in the Maranhão Amazon. This record extends the known distribution of this species approximately 1428.32 km to the east within the Amazon biome in Brazil.

Hybrid zones of Natrix helvetica and N. natrix: Phenotype data from iNaturalist and genetics reveal concordant clines and the value of species-diagnostic morphological traits

Using georeferenced photographic records of 2944 grass snakes from Germany, Austria, and northern Italy as well as previously published mtDNA sequences (n = 1062) and microsatellite data (n = 952) for grass snakes from the same regions, we examined whether or not coloration and pattern reliably allow to differentiate between Natrix natrix and N. helvetica and if so, whether the distribution patterns revealed by phenotypes and genetics are congruent. Furthermore, we used cline analyses across hybrid zones to test whether the phenotypic transition from one species to the other parallels the steep clines unveiled by genetics. Our results suggest that the two species can be reliably differentiated using coloration and pattern. The most powerful diagnostic traits are the presence/absence of side bars on the body flanks, the number of occipital spots, and the shape of the posterior dark occipital spot. The distributions of morphologically identified N. natrix and N. helvetica match their genetically confirmed ranges. Single conflicting individuals morphologically identified as N. natrix or hybrids within the distribution range of N. helvetica either represent misidentifications or translocated snakes. For the genetic markers and phenotypes, our cline analyses revealed concordant steep clines across hybrid zones. However, the southern part of the hybrid zone in Italy, for which no sufficient genetic data are available, should be studied in more detail because the phenotypic data suggest a smooth cline in this region. The unexpected high percentage of putative hybrids with dorsal stripes in this region also calls for further research. For northwestern Germany, another region for which no genetically verified records are available, iNaturalist data suggest that the contact zone of N. natrix and N. helvetica is near the Ems River and extends from there southeastwards to the region of Höxter, North Rhine-Westphalia.

Cutaneous transcriptomic profiling and candidate pigment genes in the wild discus (Symphysodon spp.)

ABSTRACT Discus (Symphysodon spp.) is a popular freshwater ornamental fish with high market value due to its extraordinary skin pigmentation. The molecular mechanisms that govern skin colouration have yet to be identified. Six skin samples from wild discus were collected in the D1 (dorsal intense black bar stripe), D2 (ventral lighter bar stripes and orange carotenoid spots) and D3 (posterior without stripe nor spot) regions of wild discus for transcriptomic profiling and analysis. Differential analysis was conducted in 3 pair-wise comparisons, D1vsD3, D2vsD3 and D2vsD1. The results demonstrated that the melanin synthesis-associated genes (ERBB4, ADCY9, WNT2, 14-3-3 proteins and TSPAN genes) were upregulated in D1 and D2 regions, whereas carotenoids metabolism-associated genes (PLIN2, AHCY, RETSAT, STARD10, TTC39B and RDH1 genes) were uniquely expressed in D2 region. Amino acid metabolism-related pathways were enriched in both the D1 and D2 regions. MAPK pathway enrichment was detected merely in the D1 region, while various transporter activities were enriched in the D2 region. Further investigations speculated the key regulator roles of GNAQ, ADCY9, 14-3-3 and TSPAN genes in black vertical bar formation. This is the first fundamental report on discus skin pigment genes that could be extended into more detailed studies in the future.

Morphology of developing larvae and a dichotomous key for five bubble-nesting Betta species (Teleostei: Osphronemidae)

The morphology of larvae of five bubble-nesting Betta species (B. imbellis, B. mahachaiensis, B. siamorientalis, B. smaragdina, and B. splendens) from Thailand was described from specimens reared in the laboratory from wild-caught parents. For all species, the mean notochord length (NL) of the larvae ranged from 2.37 to 2.58 mm. Larvae reached the flexion stage within 9-15 days (NL = 3.22-5.21 mm) and the juvenile stage within 40-45 days (standard length = 10.45-12.18 mm). The main characteristics of hatched larvae for all species were an oblong and slightly compressed body, a small and rounded head, an oval to rounded eye, and a yolk sac without oil droplets. Pre-flexion larvae for all species have an oblique, terminal mouth, and pectoral buds begin to develop after day 1. During the post-flexion larval stage, rays for the caudal, dorsal, anal, ventral, and pectoral fins begin to develop. Juveniles have a fully developed ventral fin with 2-3 dorsal, central, and ventral stripes, and a caudal spot. The minimal and maximal myomere number and fin rays differed between species. For all species, there were 1-2 dorsal spines, 7-9 dorsal rays, 9-12 pectoral rays, 1 ventral spine, 4-5 ventral rays, 2-4 anal spines, 22-28 anal rays, and 10-12 caudal rays. The different larval stages also differed in pigmentation patterns between species. Pigmentation patterns on the head (pre-orbital, sub-orbital, post-orbital, and sub-opercular bars) and longitudinal stripes on the side of the body could be used to distinguish between different larval stages as well as different species.

Two new land planarian species (Platyhelminthes: Tricladida) from the Cerrado biome in southwestern Brazil

Most Neotropical land flatworm species are known from areas of the Atlantic Forest. Herein, we describe two new land planarian species from areas of semideciduous forest in the Cerrado biome in southwestern Brazil. Paraba aurantia Marques & Leal-Zanchet, sp. nov. can be distinguished from its congeners by the wide black median band on the dorsum, eyes occupying almost the entire dorsal surface, prostatic vesicle twisted and asymmetrical with proximal portions forked, and female atrium with an ample lumen lined by a low epithelium with stratified appearance. Pasipha liviae Marques & Leal-Zanchet, sp. nov. shows a narrow longitudinal dorsal stripe, collar-shaped pharynx, and prostatic vesicle with a pear-shaped proximal portion and a globose distal portion separated by a constriction. In addition, P. liviae can be distinguished from its congeners by molecular analyses from the cytochrome c oxidase subunit I gene (COI). Phylogenetic analyses suggest that P. liviae is closely related to P. hauseri, which occurs in areas of semidseciduous forest in southern Brazil.

Multi-locus phylogeny and species delimitations of the striped-back shrew group (Eulipotyphla: Soricidae): Implications for cryptic diversity, taxonomy and multiple speciation patterns

The striped-back shrew group demonstrates remarkable variation in skull and body size, tail length, and brightness of the dorsal stripe; and karyotypic and DNA variation has been reported in recent years. In this study, we investigated the phylogenetic structure of the group, as well as speciation patterns and demographic history in Mountains of Southwestern China and adjacent mountains, including the southern Himalayas, Mts. Bashan, Wushan, and Qinling. We sequenced a total of 462 specimens from 126 localities in the known range of the group, which were sequenced and analyzed based on 6.2 kb of sequence data from two mitochondrial, six nuclear, and two Y chromosome markers. Phylogenetic analyses of the concatenated mtDNA data revealed 14 sympatric and independently evolving lineages within the striped-back shrew group, including Sorex bedfordiae, S. cylindricauda, S. excelsus, S. sinalis and several cryptic species. All concatenated data (ten genes) showed a consistent genetic structure compared to the mtDNA lineages for the group, whereas the nuclear and the Y chromosome data showed a discordant genetic structure compared to the mtDNA lineages for the striped-back shrew group. Species delimitation analyses and deep genetic distance clearly support the species status of the 14 evolving lineages. The divergence time estimation suggested that the striped-back shrew group began to diversify from the middle Pleistocene (2.34 Ma), then flourished at approximately 2.14 Ma, followed by a series of rapid diversifications through the Pleistocene. Our results also revealed multiple mechanisms of speciation in the Mountains of Southwestern China and Adjacent Mountains with complex landscapes and climate. The uplifting of the Qinghai-Tibetan Plateau, Quaternary climate oscillations, riverine barriers, ecological elevation gradients, topographical diversity, and their own low dispersal capacity may have driven the speciation, genetic structure, and phylogeographic patterns of the striped-back shrew group.

Correlated evolution of parental care with dichromatism, colors, and patterns in anurans.

Parental care is widespread and has fitness benefits. But caregiving parents incur costs including higher predation, and this may lead to selection for body colors or patterns that help mitigate the risks of caring. The evolution of coloration, including sexual dichromatism, however, can be driven by other factors, such as sexual selection. Therefore, examining the associations between parental care and color patterns may provide key insights into evolutionary patterns and selection pressures for parental care. Our comparative analysis of 988 anuran species reveals that dichromatic species are less likely to provide parental care, irrespective of the caregiving sex, and are more likely to breed in aquatic habitats. We then examined whether dorsal colors and patterns that enhance crypticity or function as aposematic signals are associated with the caregiving sex, and the modality of care (transport or stationary). Only caregiving males are more likely to have dorsal Stripes, but none of the colors (Green-Brown, Red, Yellow, Blue-Black) and other patterns (Plain, Bands, Spots, Mottled-Patches) were associated with caregiving females or the modality of care. Overall, sexual dichromatism, breeding ecology, and parental care are associated, but the evolution of caregiving behavior does not appear to influence the myriad colors and patterns characteristic of anurans globally.

A New Salamander of the Genus Onychodactylus from Central Honshu, Japan (Amphibia, Caudata, Hynobiidae)

The number of species of salamanders of the genus Onychodactylus in Japan has increased from one to six nominal species over the past decade, by taxonomic studies based not only on morphological but also molecular phylogenetic data. However, the presence of an additional cryptic species has been suggested by a series of previous studies. Here, we describe a new species, Onychodactylus pyrrhonotus sp. nov., from the Kinki, Chubu and Hokuriku Districts of central Honshu, Japan, based on morphological and genetic evidence. It belongs to the O. japonicus species complex and is the sister species of O. kinneburi from Shikoku Island and westernmost part of Honshu with 5.5% sequence divergence in the mitochondrial cytochrome b gene. The range of the new species completely overlaps with that of O. japonicus sensu stricto, and they are syntopic in at least six known localities. As shown in a previous study, reproductive isolation between these sympatric species is substantial. The new species is morphologically most easily distinguished from congeners by coloration, a sharply defined scarlet to pinkish dorsal stripe or mottling on a black background and dusty white dots on the venter.

A new catfish of the genus Trichomycterus from the Rio Paraíba do Sul Basin, south-eastern Brazil, a supposedly migrating species (Siluriformes, Trichomycteridae)

A new species of the catfish genusTrichomycterusis described from the Rio Paraíba do Sul, south-eastern Brazil. This species exhibits some morphological character states that are unique amongst congeners, including a robust opercle and a long interopercle with numerous odontodes (50–60 opercular and 90–100 interopercular), a black bar on the basal portion of the caudal fin and a dark brown flank with a well delimited dorsal yellow stripe. It also exhibits some morphological traits that are uncommon amongst congeners, such as the presence of nine pectoral-fin rays. The presence of a shallow hyomandibular outgrowth and a ventrally expanded pre-opercular ventral flap suggests that this species is closely related toT. melanopygius,T. pradensisandT. tete. The new species also differs fromT. melanopygius,T. pradensisandT. teteby having an emarginate caudal fin and a single median supra-orbital pore S6. Anecdotal evidence suggests thatT. largoperculatusandT. pradensishave migratory habits, a condition not previously reported for eastern South American trichomycterines.

Damsel in distress: is the nomenclature of Lachesis melanocephala Solórzano & Cerdas, 1986 (Serpentes, Viperidae) in need of rescue?

The neotropical viperid snake genus Lachesis Daudin, 1803 accomodates four venomous species that occur in forested areas from Central America, in Nicaragua and Costa Rica, to most of South America, southwards into southeastern Brazil and Bolivia (Campbell & Lamar 2004). This genus is unique among neotropical crotalines in having a high number of ventrals, dorsal, and cephalic scales, while also being oviparous (Campbell & Lamar 2004). Lachesis melanocephala Solórzano & Cerdas, 1986 is a large-sized viper, distributed from the Pacific coast of southwestern Costa Rica to northwestern Panama (Campbell & Lamar 2004). This species reaches up to 2.4 meters of total length, and can be diagnosed based on its uniformly black dorsal head pattern and inconspicuous postocular black stripe (Fig. 1; Campbell & Lamar 2004).

Aposematic signaling and seasonal variation in dorsal pelage in a venomous mammal.

In mammals, colouration patterns are often related to concealment, intraspecific communication, including aposematic signals, and physiological adaptations. Slow lorises (Nycticebus spp.) are arboreal primates native to Southeast Asia that display stark colour contrast, are highly territorial, regularly enter torpor, and are notably one of only seven mammal taxa that possess venom. All slow loris species display a contrasting stripe that runs cranial‐caudally along the median sagittal plane of the dorsum. We examine whether these dorsal markings facilitate background matching, seasonal adaptations, and intraspecific signaling. We analyzed 195 images of the dorsal region of 60 Javan slow loris individuals (Nycticebus javanicus) from Java, Indonesia. We extracted greyscale RGB values from dorsal pelage using ImageJ software and calculated contrast ratios between dorsal stripe and adjacent pelage in eight regions. We assessed through generalized linear mixed models if the contrast ratio varied with sex, age, and seasonality. We also examined whether higher contrast was related to more aggressive behavior or increased terrestrial movement. We found that the dorsal stripe of N. javanicus changed seasonally, being longer and more contrasting in the wet season, during which time lorises significantly increased their ground use. Stripes were most contrasting in younger individuals of dispersal age that were also the most aggressive during capture. The dorsal stripe became less contrasting as a loris aged. A longer stripe when ground use is more frequent can be related to disruptive colouration. A darker anterior region by younger lorises with less fighting experience may allow them to appear larger and fiercer. We provide evidence that the dorsum of a cryptic species can have multimodal signals related to concealment, intraspecific communication, and physiological adaptations.

Mosquito metallomics reveal copper and iron as critical factors for Plasmodium infection.

Iron and copper chelation restricts Plasmodium growth in vitro and in mammalian hosts. The parasite alters metal homeostasis in red blood cells to its favor, for example metabolizing hemoglobin to hemozoin. Metal interactions with the mosquito have not, however, been studied. Here, we describe the metallomes of Anopheles albimanus and Aedes aegypti throughout their life cycle and following a blood meal. Consistent with previous reports, we found evidence of maternal iron deposition in embryos of Ae. aegypti, but less so in An. albimanus. Sodium, potassium, iron, and copper are present at higher concentrations during larval developmental stages. Two An. albimanus phenotypes that differ in their susceptibility to Plasmodium berghei infection were studied. The susceptible white stripe (ws) phenotype was named after a dorsal white stripe apparent during larval stages 3, 4, and pupae. During larval stage 3, ws larvae accumulate more iron and copper than the resistant brown stripe (bs) phenotype counterparts. A similar increase in copper and iron accumulation was also observed in the susceptible ws, but not in the resistant bs phenotype following P. berghei infection. Feeding ws mosquitoes with extracellular iron and copper chelators before and after receiving Plasmodium-infected blood protected from infection and simultaneously affected follicular development in the case of iron chelation. Unexpectedly, the application of the iron chelator to the bs strain reverted resistance to infection. Besides a drop in iron, iron-chelated bs mosquitoes experienced a concomitant loss of copper. Thus, the effect of metal chelation on P. berghei infectivity was strain-specific.

A Salamander tale: Relative abundance, morphometrics and microhabitat of the critically endangered Mexican salamander Pseudoeurycea robertsi (Taylor, 1939)

Roberts’ False Brook Salamander (Pseudoeurycea robertsi) is a critically endangered plethodontid salamander, endemic to the Nevado de Toluca Volcano (NTV), Mexico. Little is known about the biology and ecology of this species, including its microhabitats. Thus, this study aimed to collect basic information aboutP. robertsi. We sampled fourteen forested sites in the NTV; to corroborate the correct identification of the species we used genetic data, we assessed the variation in head morphometric measurements and dorsal colouration patterns amongst localities and the microhabitat features associated withP. robertsipresence. Of the four potential salamander species,P. robertsiwas the most abundant (89.80%) and widely distributed (approximately within 130 km2) salamander in the NTV. We did not find significant variations in morphometry; however, we found significant differences in dorsal patterns between populations (in the number and size of segments of the dorsal stripe). The average total length for 185 adults was 89.15 mm (38.7–117.9 mm); we found seven patterns of dorsal stripe. We found 98% ofP. robertsiindividuals under the bark of fallen logs inAbies religiosaandA. religiosa-Pinussp. forests, with a higher number of detected salamanders in naturally-fallen logs than in cut logs (34% vs. 10%). Thus, keeping well-preservedA. religiosaforests and retaining fallen logs is essential toP. robertsiconservation.

A new species of Trachylepis (Squamata: Scincidae) from the Amhara Region, Ethiopia, and a key to the Ethiopian Trachylepis.

Ethiopia is known for its highly endemic and rich herpetofaunal diversity shaped by its biogeographical patterns. Here, a new species of skink, Trachylepis boehmei sp. nov., is described from the Ethiopian Highlands. It differs from its congeners in having smooth uncarinated dorsal scales, 26-29 scale rows around midbody, a slender body of small size, a relatively short tail, a low eye-snout distance and a unique colour pattern with 6-8 darkish brown dorsal stripes. Based on morphological characteristics, its biogeographical pattern and comparisons with other similar congeners this new species is closely related to Trachylepis megalura. A published new record of Trachylepis wingati for the Kafa region is re-examined and identified as T. megalura. An updated comprehensive key to the Trachylepis found in Ethiopia is provided. In the context of ongoing phylogenetic and taxonomic revisions of Trachylepis and its species complexes the presence of further cryptic taxa can be expected also for the Ethiopian biodiversity hotspots. Consequently, the need of further herpetological investigations in this region of ecological importance is stressed.

Transcriptome Reveals Multi Pigmentation Genes Affecting Dorsoventral Pattern in Avian Body.

Certain animals exhibit a special dorsoventral pattern with a lighter ventral side compared to the dorsal one and this phenomenon was preserved in the long-term evolution process. Birds also retain this trait. Recently, Inaba et al. (2019) found that ASIP (agouti signal protein) regulated interconversion between different melanocyte types leads to dorsal stripe pattern, which may partly explain the birds’ dorsoventral plumage color difference. In this study, we used the embryo samples of LBM (light brown mottling) ducks (Anas platyrhynchos) with white ventral and dark dorsal body parts to investigate the mechanism of dorsoventral color variation. Firstly, melanin deposition process of duck embryos was investigated. The result indicated that E13 and E16 were the active stages of melanin synthesis. Moreover, the melanin deposition on the dorsum of LBM ducks was higher than that on the ventral side throughout. Then, RNA-seq was conducted for the dorsal and ventral skin tissues from E7 (early), E13 (middle) and E19 (late) of LBM ducks. Expression pattern analysis showed that the mRNA expression of most melanin synthesis related genes were at the highest level at E13, which was consistent with the section analysis. A correlation was found between melanogenesis pathway and dorsoventral color difference by co-expression analysis. In the DEG (differentially expressed gene) analysis, we added the dorsal skin transcriptome of embryonic white and black duck of same subspecies (Anas platyrhynchos domestica) for horizontal comparison. The results showed that 8 melanogenesis related genes (TYR, TYRP1, MLANA, RAB38, OCA2, TSPAN10, MC1R, and MSLN) were the common DEGs (Differential expressed genes) in the comparisons of body parts and breeds suggesting that the underlying molecular regulatory mechanism of dorsoventral plumage color difference may be similar to that of albino and melanic duck, which were caused by the different expression of multiple genes in melanin synthesis pathway. In addition, the molecular regulation of melanin synthesis pathway in the dorsal and ventral side of LBM ducks was analyzed. In this pathway, ASIP, MC1R, TYR, and TYRP1 have differential mRNA expression. ASIP, as an upstream gene in this pathway, was likely to play a decisive role in determining the dorsoventral plumage pattern.

Dorsal stripe polymorphism of Vipera berus in south-east England

Dorsal stripe polymorphism of Vipera berus in south-east England