| isolation of a neurotoxin (alpha-colubritoxin) from a nonvenomous colubrid: evidence for early origin of venom in snakes. | the evolution of venom in advanced snakes has been a focus of long-standing interest. here we provide the first complete amino acid sequence of a colubrid toxin, which we have called alpha-colubritoxin, isolated from the asian ratsnake coelognathus radiatus (formerly known as elaphe radiata), an archetypal nonvenomous snake as sold in pet stores. this potent postsynaptic neurotoxin displays readily reversible, competitive antagonism at the nicotinic receptor. the toxin is homologous with, and ph ... | 2003 | 14708577 |
| a survey of blastocystis in reptiles. | a total of 28 species of reptiles were investigated for blastocystis using light microscopy and in vitro culture in biphasic egg slant medium. blastocystis species were detected in 8 (28.6%) of these 28 species in 3 tortoises (geochelone elephantopus, g. elegans and g. carbonaria), 3 snakes (boiga dendrophilla, python reticulatus and elaphe radiata), 1 crocodile (crocodylus porosus) and 1 iguana lizard (cyclura cornuta). the reptilian blastocystis appeared to be morphologically similar to b. hom ... | 1992 | 1495927 |
| sex chromosome associated satellite dna: evolution and conservation. | satellites visible in female but not in male dna were isolated from the snakes elaphe radiata (satellite iv, p = 1.708 g x cm-3) and bungarus fasciatus (bk1 minor, p = 1.709 g x cm-3). the satellites cross hybridize. hybridization of 3h labelled nick translated bk minor satellite dna with the total male and female dna and/or chromosomes in situ of different species of snakes revealed that its sequences are conserved throughout the snake group and are mainly concentrated on the w chromosomes. sna ... | 1980 | 7398495 |
| behaviour of sex chromosome associated satellite dnas in somatic and germ cells in snakes. | sex chromosome associated satellite dnas is isolated from the snakes elaphe radiata (sat iii) (singh et al., 1976) and bungarus fasciatus (elapidae) (minor satellite) are evolutionarily conserved throughout the suborder ophidia. an autosome limited satellite dna (b. fasciatus major satellite) is not similarly conserved. both types of satellites have been studied by in situ hybridisation in various somatic tissues and germ cells where it has been observed that the w sex chromosome remains condens ... | 1979 | 428273 |
| rhythmic contractions in chick amnio-yolk sac and snake amnion during embryogenesis. | the rhythmic movements of fetal membranes in chick and reptile embryos were studied to explore the developmental role of the extra-embryonic motor activity. in the snakes lamprophis fuliginosus and elaphe radiata, rhythmic contractions of amnion inside the developing egg were recorded from the 11th incubation day until pre-hatching stages (ca. day 60-72). the duration of these contractions averaged 2.02+/-0.27 min. the frequency ranged from 2 to 6 per 10 min and averaged 4.61+/-0.57 per 10 min. ... | 2002 | 11897197 |
| base sequence of a cloned snake w-chromosome dna fragment and identification of a male-specific putative mrna in the mouse. | a 2.5-kilobase fragment of a sex-specific satellite dna from the colubrid snake species elaphe radiata has been cloned, and its sequence has been determined. it contains 26 and 12 copies, respectively, of two base quadruplets, g-a-t-a and g-a-c-a, as its sole highly repetitious elements. southern hybridization experiments with genomic dna of the chicken, the mouse, and man indicated male sex-specific conservation of at least parts of this cloned dna. in situ hybridization experiments with metaph ... | 1982 | 6954524 |
| satellite dna and evolution of sex chromosomes. | the satellite dna (satellite iii) which is mainly represented in the female of elaphe radiata (ophidia, colubridae) has been isolated and its buoyant density has been determined (delta equals 1.700 g cm-3). in situ hybridisation of radioactive complementary rna of this satellite dna with the chromosomes of different species has revealed that it is mainly concentrated on the w sex chromosome and its sequences are conserved throughout the sub-order ophidia. from hybridisation studies these sequenc ... | 1976 | 1001165 |
| hypotensive actions of snake parathyroid glands. | parathyroid gland extracts from four different snake species, ptyas korros, ptyas mucosa, elaphe radiata, and naja naja, were prepared and their hypotensive actions were assayed in anesthetized p. korros. all extracts were hypotensive and the responses, except that of n. naja, were dose related. their potencies were, however, different in different species. these data suggest that the hypotensive property of the parathyroid hormone is probably widely distributed in submammalian vertebrates. | 1983 | 6667839 |
| snakes elaphe radiata may acquire awareness of their body limits when trying to hide in a shelter. | body awareness was studied experimentally in the rat snakes elaphe radiata. the experimental design required that the snakes take into account the limits of their bodies when choosing a suitable hole for penetration into the shelter. the experimental setup consisted of two compartments, a launch chamber and a shelter, separated by a partition with openings of different diameters. the diameters of the holes and/or their position in the partition were changeable. the subjects were 20 snakes divide ... | 2019 | 31248003 |