Year: 2012
Type: editorial
Abstract: A picture, as the saying goes, is worth a thousand words. In fact, humans have used every imaginable medium to pictorially describe their stories and the world around them. Among these media is tapestry, a form of textile art, invented thousands of years ago and admired to this date for its unique texture and coloration. Tapestries are made from two interwoven threads, the warp, running the length of the fabric, and the weft, running its width. Unlike in cloth fabrics, however, only the weft threads are visible in tapestry and the warp threads are hidden behind them. Why am I writing about this? Well, in a great review in this issue, tapestry is the metaphore that Marcus Kronforst and colleagues use to describe the fantastic color variations that we see in nature. The authors present many fascinating examples of color variations in flies, butterflies, lizards and additional emerging model systems but go far beyond these descriptions by focusing on the crucial question of the underlying molecular genetic mechanisms. These they call the threads in nature’s tapestry, referring to the warp that hides behind the weft. As the authors point out, the study of color patterns is ideal to answer fundamental questions in evolution. Is variation generated by a small number of genes with large effects? Can different genes, and perhaps different pathways, generate similar patterns even in closely related species? To what extent is evolutionary potential constrained by the molecular pathways that regulate development and life of an organism? Are regulatory or structural changes in genes more important for phenotypic evolution? These and other questions are dealt with in considerable detail in this review, and so it presents a must-read not only for us specialists of pigment cell biology but also for evolutionary biologists in general. And for those of you who want to know more about the evolution of pigment patterns in birds and mammals, I can only say, stay tuned, there will likely be a sequel. Compared with the integument of many animals, human skin offers little variations in pigment patterns yet a lot in variation of both inherited and environmentally induced pigment intensity. In extension of previous work, Choi and colleagues define the aminoacid sequence LCKC of the keratinocyte- and fibroblast-derived paracrine neuregulin-1 as the minimal motif capable of regulating pigment production in human melanocytes without influencing their proliferation. Food for thought is also provided in a letter by Tonks et al., who show that conditional deletion of the tumor suppressor Brca1 in melanocytes can lead to a piebald coat phenotype in mice that is associated with a p53-dependent loss of melanocytes. Several other articles deal with melanoma, including the role of genetic variants of modulators of interleukin-1β for the appearance of sporadic melanoma (Verma et al.), an analysis of gene expression changes in cutaneous melanoma following high-dose chemotherapy (Wouters et al), or the finding that melanoma-derived factors induce monocytes to become cells with gene expression characteristics of pro-invasive tumor-associated macrophages (Wang et al.). As always, I hope you will enjoy reading through these pages and recommend our journal to all your colleagues both from within and outside the pigment and melanoma field.
Source: Pigment Cell & Melanoma Research
Author: Heinz Arnheiter
Language: English
Subfield: Cell Biology
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2009275099