(a.) Protected or covered by bony or horny plates, or large scales.
Example Sentences:
(1) The dermis of reticulate scales does not induce beta stratum formation, but it does support differentiation of a beta stratum by the determined 15-day scutate scale epidermis.
(2) Tenascin's initial appearance and pattern of distribution in the scutate scale dermis and its abnormal expression in the scaleless dermis suggest that morphogenesis plays a significant role in regulation of its expression.
(3) This study also suggests that all basal cells of the presumptive scutate scale epidermis are initially endowed with the ability to generate cells that form a beta stratum.
(4) This study shows that different patterns of scutate scale type beta keratins are accumulated in the three adjacent structures of the embryonic chick beak: periderm, egg tooth, and cornified beak.
(5) The results show that the germinative cell population of the 15-day scutate scale epidermis is committed to generating suprabasal cells that follow their appendage-specific pathways of histogenesis and terminal differentiation.
(6) The chorionic epithelium formed the appropriate epidermis with a fully developed stratum corneum in response to both spur and scutate scale dermises.
(7) The expression of two previously uncharacterized polypeptides produced in epidermal cells of chick reticulate and scutate scales during late embryonic scale histogenesis and in hatchling birds has been studied biochemically and immunologically.
(8) We have found that the extracellular matrix molecule, tenascin, first appears in the scutate scale dermis at 12 days of development when the scale ridge is established.
(9) Seven beta keratin polypeptides were translated in vitro and could be identified by their positions in two-dimensional gels among the detergent-insoluble extracts of scutate scale epidermis.
(10) This selective expression of beta keratin genes in specific regions of the developing scutate scale suggests that epidermal-dermal interactions provide not only for morphological events, but also for control of complex patterns of histogenesis and biochemical differentiation.
(11) Correlations between the patterns of beta-keratin expression and histological events suggest that the brief accumulation of beta-keratin mRNA in scaleless skin and normal reticulate scales is related to the formation of the subperiderm (a protective layer of cells, peculiar to embryonic skin) while the continuous accumulation of beta-keratin mRNA during scutate scale development reflects the formation of a beta stratum.
(12) Neither the histidine rich "fast" proteins (HRPs), which are expressed in embryonic scutate scales and feathers, nor the avian cytokeratin associated proteins (cap-1 and cap-2), which are expressed in scutate and reticulate scales, are expressed in any of the embryonic beak structures or in the claw.
(13) Recent studies have shown that the dermis of scutate scales is involved in the expression of the beta keratin gene products, which characterize terminal differentiation of the epidermis on the outer scale surface (Sawyer et al.
(14) The egg tooth, which is the rounded elevation on the dorsal surface of the upper beak, and the embryonic claw accumulate greatly reduced levels of 2,3 and p2,3 compared to scutate scale.
(15) While it is well established that epidermal-dermal interactions are important for the regional expression of the beta keratin genes in the avian scutate scales and feathers, little is known about the expression of beta keratins in other epithelial structures such as the tongue.
(16) The temporal appearance of beta keratin mRNA and the corresponding polypeptides was followed during scutate scale development.
(17) Morphogenesis of the anterior metatarsal skin (scutate scale region), from 9.5 to 12 days of development, results in the formation of orderly patterned scale ridges.
(18) This observation suggested the possibility that commitment to beta stratum formation might be occurring as the outer epidermal surface of each scutate scale first becomes established between 12 and 13 days of development.
(19) In the anterior metatarsal region of the chicken, morphogenesis results in the formation of distinct overlapping scutate scales.
(20) To examined the ability of the presumptive scutate scale epidermis to generate beta strata in the absence of the inductive scutate scale dermis, scutate scale epidermis from 11-, 12-, and 13-day embryos was recombined with 15-day reticulate scale dermis and grown for 7 or 9 days.
Scute
Definition:
(n.) A small shield.
(n.) An old French gold coin of the value of 3s. 4d. sterling, or about 80 cents.
(n.) A bony scale of a reptile or fish; a large horny scale on the leg of a bird, or on the belly of a snake.
Example Sentences:
(1) The number of the long thoracic chaetae of heterozygote females born from crosses between a scute stock and various wild strains can be less than eight.
(2) Immunocytochemical studies demonstrate that the achaete-scute and daughterless genes are required for proper expression of cpo in the PNS but not in other cells that express cpo.
(3) These and other data suggest that the excess function phenotypes of Hw mutations are generated by an increase in achaete or scute transcripts.
(4) Surprisingly, we also find that the level of achaete-scute activity influences the level of hairy expression, thereby providing feedback control upon achaete-scute activity and sensory organ formation.
(5) The scutes were ingested during a period of neglect by the owner.
(6) Although different at their 3' untranslated regions, both cDNAs predict a protein with primary amino acid sequence homology to the previously described amphipathic helix-loop-helix DNA binding and dimerization motif of the Ly1-1, myc, MyoD, immunoglobulin enhancer binding, daughterless, and achaete-scute families of genes.
(7) We have determined the nucleotide sequence of two genes of the achaete - scute complex (AS-C) and show that they are homologous to two previously sequenced members of the same locus.
(8) All three encode a sequence similar to one of the conserved domains of representatives of the vertebrate myc gene family which is also present in the deduced protein sequences of the Drosophila achaete-scute gene complex.
(9) The pro-neural class of genes, for example, the achaete-scute complex, participates in the initial decision to make each uniquely positioned neuroblast or sensory organ, but are initially expressed in groups of cells.
(10) However, replacing the basic region of MyoD with the analogous sequence of other HLH proteins (the immunoglobulin enhancer binding E12 protein or T4 achaete scute protein) allows DNA binding in vitro, yet abolishes muscle-specific gene activation.
(11) The predicted protein product of the lyl-1 gene contains a potential helix-loop-helix DNA binding motif also found in several proteins involved in the control of cellular proliferation and differentiation: all members of the Myc family, MyoD1, myogenin, the Drosophila achaete-scute, twist, and daughterless proteins, and two recently described immunoglobulin enhancer binding proteins.
(12) According to these and previous data, the AS-C is organized, distally to proximally, as follows: the achaete region, with most of its DNA (10 kb) located upstream from the putative achaete (T5) gene; an intermediate region, approximately 18 kb long, whose deletion only weakly affects the scute function; and the scute region, with most of the DNA critical for its function extending 4-5 kb upstream and 50 kb downstream of the putative scute (T4) gene.
(13) Essentially, the double alterations of yellow and scute phenotypes constitute more than 40% of all derivatives.
(14) The achaete-scute T3 and MyoD proteins do not form kappa E2-binding heterodimers together, and no active complex with N-myc was evident.
(15) The achaete and scute mutations lead to reduction of bristles and hairs on head and thorax.
(16) The need for the technique was motivated by a study describing longitudinal growth data from the annuli on abdominal scutes of groups of western painted turtles.
(17) Family selection for directional asymmetry in the expression of the Drosophila melanogaster mutant scute had no result.
(18) The deduced amino acid sequence of clone Myf-5 reveals a region which is highly similar to myc proteins and the developmental factors from Drosophila encoded by the achaete scute locus and the twist gene.
(19) We have confirmed this model by showing that misexpression of the achaete-scute T4 gene induces ectopic Sxl expression and male-specific lethality, confirming that achaete-scute T4 is the sisterless-b counting element.
(20) In the mutants, neuronal precursor cells do not differentiate, suggesting that Hairless might be involved in specifying or realizing neuronal fate in the fly, similar to the 'pro-neural' genes of the achaete-scute complex.