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Fibroblast growth factors (Fgfs) encode small signaling proteins that help regulate embryo patterning. Fgfs fall into seven families, including FgfD. Nonvertebrate chordates have a single FgfD gene; mammals have three (Fgf8, Fgf17, and Fgf18); and teleosts have six (fgf8a, fgf8b, fgf17, fgf18a, fgf18b, and fgf24). What are the evolutionary processes that led to the structural duplication and functional...
Rupert Riedl's concept of burden forms a causal hypothesis on organismic integration and evolutionary constraints. Defined as the hierarchically nested interdependence of characters within the organism, burden was seen as (1) defining and conserving body plans and (2) constraining and directing evolutionary trajectories. A review of the components of the burden concept reveals important consistencies...
The paucity of data on sexual development of anuran amphibians has played an important role in the recent controversy over atrazine exposure. Although some studies have demonstrated the presence of abnormal gonads in control treatments, others have not, leading to varying interpretations of the effects of atrazine exposure on sexual development. However, the timing of development varies among anuran...
Using bioinformatic methods we have detected the genes of 40 keratin‐associated β‐proteins (KAβPs) (β‐keratins) from the first available draft genome sequence of a reptile, the lizard Anolis carolinensis (Broad Institute, Boston). All genes are clustered in a single but not yet identified chromosomal locus, and contain a single intron of variable length. 5′‐RACE and RT‐PCR analyses using RNA from...
Developmental plasticity plays a major role in evolution and provides an excellent context for unravelling the ecological implication of variation in abiotic factors to which developing fish are subjected. Water velocity has been known to induce plasticity in salmonids, but the ontogenetic component of these changes is poorly documented. Newly hatched specimens of rainbow trout (Oncorhynchus mykiss...
Phenotypic variation is a fundamental component of the process of evolution and understanding the factors that create this variation is critical to investigations of this process. We test the hypothesis that phenotypic variation created under natural incubation conditions will differ from that created under constant laboratory conditions in a reptile species with temperature‐dependent sex determination...
During pregnancy, uterine vasculature of live‐bearing lizards proliferates to support embryonic growth and development. Vascular endothelial growth factor (VEGF) is the most potent of a suite of growth factors responsible for uterine vascularization in mammals. We have sequenced VEGF mRNA transcripts expressed in the uterus of oviparous and viviparous Australian skinks, and compared uterine VEGF expression...
Biologists have long recognized the importance of gene pleiotropy, that is, single genes affect multiple traits, which is one of the most commonly observed attributes of genes. Yet the extent of gene pleiotropy has been seriously under‐explored. Theoretically, Fisher's model assumed a universal pleiotropy, that is, a mutation can potentially affect all phenotypic traits. On the other hand, experimental...
We studied early embryonic development of zebra fish and tested if changes in the external raising conditions could elicit phenotypic changes during the phylotypic stage which, classically, is considered as a conserved embryonic stage. In particular, we tested for internal constraints, plasticity, and heterochrony during the early embryonic development. Our tested hypotheses predict (i) no change...
Collagen type 2 α1 (Col2A1) protein is a major component of the cartilaginous extracellular matrix (ECM) in vertebrates. Over the past two decades, the evolutionary origin of Col2A1 has been studied at the biochemical and molecular levels in extant jawless vertebrates (hagfishes and lampreys). Although these studies have contributed to our understanding of ECM protein evolution, the expression profile...
Notice of Withdrawal: The following article from the Journal of Experimental Zoology Part B: Molecular and Developmental Evolution, “Evidence for duplicated Hox genes in polyploid Cyprinidae fish of common carp, crucian carp, and silver crucian carp” by Yuan J, He Z, Yuan X, Jiang X, Sun X, Zou S, published online on 29 Sept 2009 in Wiley InterScience (www.interscience.wiley.com), has been withdrawn...
The modal number of lumbar vertebrae in modern humans is five. It varies between three and four in extant African apes (mean=3.5). Because both chimpanzees (Pan troglodytes) and gorillas (Gorilla gorilla) possess the same distributions of thoracic, lumbar, and sacral vertebrae, it has been assumed from parsimony that the last common ancestor (LCA) of African apes and humans possessed a similarly short...
The visual system of indirectly developing insects such as Drosophila passes through two phases of development. Larval eyes form in the embryo, whereas the adult compound eyes form during metamorphosis. Comparative evidence implies that this biphasic mode of visual system development evolved from the continuously developing eye of directly developing insects. We investigated the developmental basis...
Compared with other diploid teleosts (2n=48), anguilloid fish have a specialized karyotype (2n=38) and remarkable morphological variation, and represent one basal group species of teleosts. To investigate the Hox gene/cluster inventory in basal teleosts, a PCR‐based survey of Hox genes in the Japanese eel (Anguilla japonica) was conducted with both gene‐specific and homeobox‐targeted degenerate primers...
The neural crest (NC) is a transient population of multipotent progenitors arising at the lateral edge of the neural plate in vertebrate embryos, which then migrate throughout the body to generate diverse array of tissues such as the peripheral nervous system, skin melanocytes, and craniofacial cartilage, bone and teeth. The transient nature of neural crest stem cells make extremely challenging to...
Post‐transcriptional regulations play a crucial role during spermatogenesis of the vertebrates. Chromatoid body (CB) is a characteristic spermatid organelle that is supposed to exert its role in post‐transcriptional processes, but its real functions remain largely unknown. Here we report identification of Mago from the rice field eel, and show its evolutionary conservation, differential expression...
The c‐Jun N‐terminal kinases (JNKs) are members of the mitogen‐activated protein kinase family. Their functions in regulating animal development have been well studied in both invertebrates and vertebrates. However, it remains to be determined whether they play a role in sex determination. Here we present first evidence to show that expression of JNK1 displays distinct patterns during sex reversal...
The pectoral apparatus (shoulder girdle plus sternum) of amniotes plesiomorphically includes an unpaired element of dermal origin. In crocodylians, lepidosaurs, and nontherian synapsids (monotremes and their ancestors) this element is identified as the interclavicle, in Testudines (turtles and tortoises) as the entoplastron, and in Aves as the furcula. We investigated embryonic development of the...
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