Development Genes and Evolution

Dmrt (doublesex and mab-3 related transcription factor) is a protein family of transcription factors implicated in sexual regulation. Dmrt proteins are widely conserved and known for their involvement in sex determination and differentiation across species, from invertebrates to humans. In this study, we identified a novel gene with a DM (doublesex/Mab-3)-domain gene in the river prawn, Macrobrachium nipponense, which we named MniDmrt1B due to its similarities and close phylogenetic relationship with Dmrt1B in Macrobrachium rosenbergii...

Bilateria encompass the vast majority of the animal phyla. As the name states, they are bilaterally symmetric, that is with a morphologically clear main body axis connecting their anterior and posterior ends, a second axis running between their dorsal and ventral surfaces, and with a left side being roughly a mirror image of their right side. Bone morphogenetic protein (BMP) signalling has widely conserved functions in the formation and patterning of the second, dorso-ventral (DV) body axis, albeit to different extents in different bilaterian species...

Most of annelids grow all over their asexual life through the continuous addition of segments from a special zone called "segment addition zone" (SAZ) adjacent to the posterior extremity called pygidium. Amputation of posterior segments leads to regeneration (posterior regeneration-PR) of the pygidium and a new SAZ, as well as new segments issued from this new SAZ. Amputation of anterior segments leads some species to regeneration (anterior regeneration-AR) of the prostomium and a SAZ which produces new segments postero-anteriorly as during PR...

Current sequencing technology allows for the relatively affordable generation of highly contiguous genomes. Technological advances have made it possible for researchers to investigate the consequences of diverse sorts of genomic variants, such as gene gain and loss. With the extraordinary number of high-quality genomes now available, we take stock of how these genomic variants impact phenotypic evolution. We take care to point out that the identification of genomic variants of interest is only the first step in understanding their impact...

As proposed by Wilhelm Roux in 1885, the key goal of experimental embryology ("Entwicklungsmechanik") was to elucidate whether organisms or their parts develop autonomously ("self-differentiation") or require interactions with other parts or the environment. However, experimental embryologists soon realized that concepts like "self-differentiation" only make sense when applied to particular parts or units of the developing embryo as defined both in time and space. Whereas the formation of tissues or organs may initially depend on interactions with surrounding tissues, they later become independent of such interactions or "determined...

Johnston's organ (Jo) acts as an antennal wind-sensitive and/or auditory organ across a spectrum of insect species and its axons universally project to the brain. In the locust, this pathway is already present at mid-embryogenesis but the process of fasciculation involved in its construction has not been investigated. Terminal projections into the fine neuropilar organization of the brain also remain unresolved, information essential not only for understanding the neural circuitry mediating Jo-mediated behavior but also for providing comparative data offering insights into its evolution...

Hair follicle growth is cyclical, and hair cycle dysfunction can lead to hair follicle-related disorders, including alopecia and hirsutism. The objective was to investigate the influence and underlying mechanism of Krüppel-like factor 4 (KLF4) overexpression on hair follicle growth and development in C57BL/6 mice. To provide a theoretical basis for the biological functions of KLF4 gene in hair follicle development and hair follicle cycle, mice were assigned to three groups: experimental, overexpressing KLF4 (Ad-KLF4); control, expressing green fluorescent protein (Ad-NC); and blank, no treatment...

Domestication transforms once wild animals into tamed animals that can be then exploited by humans. The process entails modifications in the body, cognition, and behavior that are essentially driven by differences in gene expression patterns. Although genetic and epigenetic mechanisms were shown to underlie such differences, less is known about the role exerted by trans-regulatory molecules, notably transcription factors (TFs) in domestication. In this paper, we conducted extensive in silico analyses aimed to clarify the TF landscape of mammal domestication...

Spiders represent an evolutionary successful group of chelicerate arthropods. The body of spiders is subdivided into two regions (tagmata). The anterior tagma, the prosoma, bears the head appendages and four pairs of walking legs. The segments of the posterior tagma, the opisthosoma, either lost their appendages during the course of evolution or their appendages were substantially modified to fulfill new tasks such as reproduction, gas exchange, and silk production. Previous work has shown that the homeotic Hox genes are involved in shaping the posterior appendages of spiders...

The African bichir (Polypterus senegalus) is a living representative of Polypteriformes. P. senegalus possesses teeth composed of dentin covered by an enameloid cap and a layer of collar enamel on the tooth shaft, as in lepisosteids. A thin layer of enamel matrix can also be found covering the cap enameloid after its maturation and during the collar enamel formation. Teleosts fish do not possess enamel; teeth are protected by cap and collar enameloid, and inversely in sarcopterygians, where teeth are only covered by enamel, with the exception of the cap enameloid in teeth of larval urodeles...

Thermal plasticity of melanin pigmentation patterns in Drosophila species has been studied as a model to investigate developmental mechanisms of phenotypic plasticity. The developmental process of melanin pigmentation patterns on wings of Drosophila is divided into two parts, prepattern specification during the pupal period and wing vein-dependent transportation of melanin precursors after eclosion. Which part can be affected by thermal changes? To address this question, we used polka-dotted melanin spots on wings of Drosophila guttifera, whose spot areas are specified by wingless morphogen...

Stem cell division contributes to the generation of various cell types during animal development, especially a diverse pool of neural cells in the nervous system. One example is reiterated unequal stem cell divisions, in which a large stem cell undergoes a series of oriented unequal divisions to produce a chain of small daughter cells that differentiate. We show that reiterated unequal stem cell divisions are involved in the formation of the brain in simple chordate appendicularians (larvaceans). Two large neuroblasts in the anterior and middle of the brain-forming region of hatched larvae were observed...

One hurdle in the development of zebrafish models of human disease is the presence of multiple zebrafish orthologs resulting from whole genome duplication in teleosts. Mutations in inositol polyphosphate 5-phosphatase K (INPP5K) lead to a syndrome characterized by variable presentation of intellectual disability, brain abnormalities, cataracts, muscle disease, and short stature. INPP5K is a phosphatase acting at position 5 of phosphoinositides to control their homeostasis and is involved in insulin signaling, cytoskeletal regulation, and protein trafficking...

Cranial neurogenic placodes have been considered vertebrate innovations. However, anterior neural plate border (ANB) cells of ascidian embryos share many properties with vertebrate neurogenic placodes; therefore, it is now believed that the last common ancestor of vertebrates and ascidians had embryonic structures similar to neurogenic placodes of vertebrate embryos. Because BMP signaling is important for specifying the placode region in vertebrate embryos, we examined whether BMP signaling is also involved in gene expression in the ANB region of ascidian embryos...

Gastrulation is a critical event whose molecular mechanisms are thought to be conserved among vertebrates. However, the morphological movement during gastrulation appears to be divergent across species, making it difficult to discuss the evolution of the process. Previously, we proposed a novel amphibian gastrulation model, the "subduction and zippering (S&Z) model". In this model, the organizer and the prospective neuroectoderm are originally localized in the blastula's blastocoel roof, and these embryonic regions move downward to make physical contact of their inner surfaces with each other at the dorsal marginal zone...

Cold-inducible RNA-binding protein (CIRBP) responds to a wide array of cellular stresses such as cold shock, hypoxia, and inflammatory responses. However, functional studies of CIRBP in jawless vertebrates are limited. In this study, a CIRBP homolog from the jawless vertebrate lamprey (Lethenteron reissneri) was cloned and characterized (named Lr-CIRBP). The cDNA fragment of Lr-CIRBP has a 516 bp open reading frame (ORF) that encodes 171 amino acids, comprising a glycine-rich region at the C-terminal, similar to higher vertebrates but slightly shorter, and an RNA recognition motif (RRM) domain at the N-terminus...

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The core molecular mechanisms of dorsal organizer formation during gastrulation are highly conserved within the chordate lineage. One of the key characteristics is that Nodal signaling is required for the organizer-specific gene expression. This feature appears to be ancestral, as evidenced by the presence in the most basally divergent chordate amphioxus. To provide a better understanding of the evolution of organizer-specific gene regulation in chordates, we analyzed the cis-regulatory sequence of amphioxus Chordin in the context of the vertebrate embryo...

Spiders have emerged as one of the leading model organisms in many research fields due to their compelling biology. Often, scientific investigations involving the use of spiders face inevitable problems associated with the lack of specimens from laboratory stock, resulting in difficulties in yielding reproducible investigations for predictive research. Thus, several species of well-studied spiders, including Parasteatoda tepidariorum, have been successfully bred for such purposes. Crossopriza lyoni is a Haplogyne spider, globally distributed and widespread in human inhabitants, prompting interest in various studies over the last decades...

During primitive streak formation in the chick embryo, cells undergo mesendoderm specification and convergent extension at the same time and in the same cells. Previous work has implicated cVG1 (GDF3) as a key factor for induction of primitive streak identity and positioning the primitive streak, whereas FGF signalling was implicated in regulating cell intercalation via regulation of components of the WNT-planar cell polarity (PCP) pathway. FGF has also been reported to be able to induce a primitive streak (but lacking the most axial derivatives such as notochord/prechordal mesendoderm)...