Feathers are complex, branched keratin structures that exhibit a diversity of pigmentation patterns. Feather pigments are transferred into developing feather keratinocytes from pigment cells that migrate into the tubular feather germ from the dermis. Within-feather pigment patterns are determined by differential pigmentation of keratinocytes within independent barb ridges during feather develop...

Natural populations of beach mice exhibit a characteristic color pattern, relative to their mainland conspecifics, driven by natural selection for crypsis. We identified a derived, charge-changing amino acid mutation in the melanocortin-1 receptor (Mc1r) in beach mice, which decreases receptor function. In genetic crosses, allelic variation at Mc1r explains 9.8% to 36.4% of the variation in sev...

Background: Melanin pigmentation of the gingiva occurs in allethnicities. Excessive pigmentation is an esthetic concern thathas increased awareness about depigmentation procedures. Thepurpose of the present study was to correlate the skin color andgender with the intensity and distribution of gingival melaninpigmentation in a group of South Indians for treatment strategies.Method: Two hundred m...

BACKGROUND Clinicians are searching for new methods to diagnose and predict the course of androgenetic alopecia noninvasively. OBJECTIVE Our aim is to evaluate trichoscopic findings and their relations with disease severity in androgenetic alopecia. METHODS The videodermatoscopic findings of 143 female and 63 male patients with androgenetic alopecia were compared with each other, with those...

The mullet species under the family Mugilidae, considered to be a commercially important teleost, are mostly found in coastal waters throughout world, distributed tropical, subtropical and temperate areas. In terms of taxonomic study, biogeography distribution pattern mullets remain unclear due difficulty separating based on morphological characters. Thus, there is need study taxonomy Mugilidae...

BACKGROUND Dermoscopy is a helpful tool that can assist experienced users improve the diagnostic accuracy for pigmented lesions in acral sites. As a simplification, one can assume that if pigment is found predominantly in the furrows, the lesion can be considered benign, and if the pigmentation is present predominantly on the ridges, the lesion should be considered malignant. The differentiatio...

Scientists have long known that variation in animal color patterns carry far more than cosmetic signifi cance. Darwin fi rst connected pigmentation with adaptive advantage, noting that male fi nches with bright red plumage enjoyed greater reproductive success than their drab competitors. Explaining why coloration confers such advantages, however, has proved somewhat easier than showing how it a...

We present a model to explain how the neurosecretory system of aquatic mollusks generates their diversity of shell structures and pigmentation patterns. The anatomical and physiological basis of this model sets it apart from other models used to explain shape and pattern. The model reproduces most known shell shapes and patterns and accurately predicts how the pattern alters in response to envi...

We explore numerically the formation of Turing patterns in a confined circular domain with small aspect ratio. Our results show that stable fivefold patterns are formed over a well defined range of disk sizes, offering a possible mechanism for inducing the fivefold symmetry observed in early development of regular echinoids. Using this pattern as a seed, more complex biological structures can b...