昆明市宠物市场爬行动物贸易调查

目的了解昆明市宠物市场上销售爬行动物的种类、数量、来源、价格及市场管理情况,为爬行类资源的保护和管理提供基础资料。方法采用观察和访谈相结合方式进行调查。结果昆明市6个宠物市场爬行动物类共有35种,其中蛇类14种,隶属3科12属;蜥蜴类6种,隶属4科5属;龟类15种,隶属6科12属。国外物种15种,占市场种类的42.9%;国内物种20种,占57.1%。依据《中国物种红色名录》(2004),1种为极危,4种为濒危,2种为易危;属于CITES(2013)附录Ⅱ有5种,附录Ⅲ有3种;属于国家重点保护的有2种。结论昆明市宠物市场爬行动物贸易缺乏相应的法制法规进行监督管理,应尽早制定规章制度加强对市场的管理,使市场更加规范有序。     

Endemic species of grasses in Mexico: a phytogeographic approach

The Poaceae family includes approximately 700 genera and 10000 species, and Mexico is considered one of its most important centers of diversity and endemism. A total of 256 taxa (including 16 subspecific taxonomic units), belonging to 65 genera, are endemic to Mexico. Some of them are close relatives of important crops, while others are used in different ways all over the country. The aim of this paper is to discuss the distribution patterns at state level of the Mexican endemic species of Poaceae. Using cluster strategies, the states are classified according to their floristic similarities. Later, hotspots of endemism are identified, in order to discuss their role in conservation strategies. To evaluate the importance of each state in the conservation of the Mexican endemic Poaceae, two iterative complementarity methods were also used. Our results show that the largest concentration of endemic taxa occurs in a few states, such as Jalisco, Mexico, Michoacán, Durango, Oaxaca, Veracruz, San Luis Potosi, Chiapas, Chihuahua, Puebla, and Coahuila. The results also show that there are some patterns in the relationship to its endemism that seem to reflect important diversification trends in the family. Accordingly, 31% of the grass genera of Mexico have at least one endemic species, and 16.7% of the genera have only one endemic species. In contrast, six genera contribute 47.2% of the total number of grass endemics in Mexico. The Chloridoideae contributes 42.9% of the total grass endemic species of Mexico, whereas the Panicoideae includes 24.6%, and the Pooideae 19.8%. Thus, these three subfamilies contribute about 87% of the species endemism. On the basis of the habitat and distribution patterns of these subfamilies, two main areas of endemicity can be identified. The first area is located in warm habitats, whereas the second is related to temperate and high regions. The cluster analyses indicate the occurrence of four state groups whose phytogeographical explanation is discussed on the basis of a floristic regionalization of Mexico. The results also indicate the need to establish a relatively high number of sites and states for the conservation of 256 endemic taxa. The elevated number of sites required to conserve the Mexican endemic Poaceae is mainly due to the fact that many taxa have a restricted distribution pattern. On the basis of the patterns obtained, a few proposals are presented for undertaking the establishment of conservation priorities of these taxa.     

A proposal for the conservation of the family Cucurbitaceae in Mexico

The pantropical Cucurbitaceae is one of the most important families ofvascular plants. The family includes 118 genera and 825 species, and Mexicois one of its most important centers of diversity, with 34 genera and 141species and subspecific taxa, including 13 cultivated ones. Five genera and 70taxa are endemic to the country. Some Mexican and Latin American wild speciesare close relatives of important crops, and others are employed as food ormedicine. Accordingly, in countries like Mexico the conservation of members ofthis family should be a priority. In this paper a list of members ofCucurbitaceae occurring in Mexico and their distribution patterns at state levelare discussed. Using cluster strategies, the states were classified according totheir floristic similarities. Hotspots of total diversity and endemismsat state level are identified, in order to discuss their role in futureconservation strategies. Iterative methods applied by conservation biology todetermine the best places for conservation are used to identify hierarchicallythe most important states that merit to be considered in this goal. Resultsindicate that implementing conservation strategies in half of the states wouldallow the protection of all the diversity found in the country, especially theendemisms. The combination of the results provided by the different methods isalso discussed as a possibly more efficient way to propose conservationstrategies for important species of the family.     

People and mammals in Mexico: conservation conflicts at a national scale

Contrary to much supposition, recent studies, typically at global and continent-wide scales, have documented a positive relationship between spatial variations in human density and species richness of selected groups of vertebrates. How widely this pattern generalises remains unknown, and particularly how well it extends to analyses at the extent of a country and at reasonably fine spatial resolution, and to regions with well-developed mechanised agricultural infrastructure. Here, we demonstrate that there is a positive relationship between human density and mammal species richness across Mexico, and that this appears to follow from similar patterns between spatial environmental variation (particularly net primary productivity, precipitation and temperature) and both human density and mammal species richness. These results have some potentially important implications for conservation planning in the region, particularly given that optimal complementary sets of areas to represent all mammal species in Mexico tend to lie in areas of disproportionately high human density.     

Conservation with a Gun: Understanding Landowner Attitudes to Deer Hunting in the Scottish Highlands

Conservation conflicts are often difficult to resolve due to a combination of poorly defined property rights, inadequate funding, high transaction costs, and contrasting value systems among stakeholders. This paper explores these barriers to collaboration in the context of the emerging deer crisis in the Scottish Highlands, where deer numbers are now higher than at any time in recorded history. In particular we explore the potential role of recreational hunting in the government’s strategy to contain rising deer numbers from the landowners’ perspective. Using both qualitative and quantitative analysis we find that hunting traditions and personal preferences, reinforced by antipathy to conservationists and their perceptions of land stewardship, are the major barriers to shooting more deer for conservation objectives. We conclude that an expansion of commercial hunting opportunities is the best practical approach to resolving the current conflict over deer, but conservationists and landowners must work together to create a more positive context for hunter-conservation initiatives and activities.

Two decades of wildlife rehabilitation in Greece: Major threats,admission trends and treatment outcomes from a prominent rehabilitation centre

The ultimate goal of Wildlife Rehabilitation Centres is to release wild animals back into the wild, after providing care and treatment according to protocol. The data collected during the process though, can be an invaluable resource of information, and act as a proxy of the anthropogenic impact on wild populations. They can even help to propose mitigation and conservation measures that could reduce pressure on wildlife. In the current study, we analysed the records of ANIMA, a prominent Wildlife Rehabilitation Centre in Athens, Greece, over a 17-year study period. Using a database of 54,445 animals representing 353 species from 104 families, we draw connections between the magnitude of admission causes and their predicted outcomes based on the animals admitted. We found that while many animals that are admitted as orphans or after living in captivity have good chances of being released, that is not the case for victims of electrocution or domestic animal attacks. Illegal shooting is clearly present in our data and seems to also affect wild populations negatively. We highlight the importance of Wildlife Rehabilitation Centres’ data towards understanding and defining human impact on wildlife, the importance of communicating the results to policymakers for biodiversity conservation and even proposing possible management directions. In that context, we also urge for more population monitoring field studies, so that admission data can be accurately combined and make meaningful predictions for the status of wild populations.     

Aquatic bird distributions in Mexico: designing conservation approaches quantitatively

The aquatic birds of Mexico include both a rich fauna of residents and a significant proportion of migratory species that breed in Canada and the United States, yet their distribution and richness patterns remain poorly known. We developed a detailed database of occurrences, and estimated distributions using niche modeling interpolations for 134 species associated with wetlands. Validations of the resulting maps indicated that the niche-modeling approach yields a useful picture of aquatic bird species distributions in the country. Richness patterns among aquatic birds differ from those for landbirds: species richness is concentrated in coastal areas, but endemism is focused in the Transvolcanic Belt and the Altiplano. Place prioritization exercises identified sets of areas that would maximize the protection of this diversity.     

Avian diversity in a priority area for conservation in North America: the Janos-Casas Grandes Prairie Dog Complex and adjacent habitats in northwestern Mexico

From February 1994 to January 2004, we studied the avifauna of a 25,000-ha area centered on the Janos-Casas Grandes Prairie Dog Complex of Northwestern Chihuahua, Mexico. Avian diversity totalled 227 species, of which 86 (38%) were residents, 78 (35%) winter migrants, 30 (14%) summer migrants, 27 (11%) transients, and 6 (2%) accidental vagrants. Around 84 (38%) species were observed in at least two habitat types, with riparian areas supporting the highest observed diversity of birds (112 species). Of the 143 species observed in only one habitat type, 44 (30%) occurred in riparian areas, 35 (26%) in association with ponds and aquatic vegetation, 28 (20%) in grasslands, 16 (11%) in the oak woodland–grassland ecotone, 12 (9%) in mesquite scrubland, 5 (3%) around human settlements, and 3 (2%) in crop fields. In particular, summer rains influenced the abundance and/or distribution of several species in grasslands such as the long-billed curlew (Numenius americanus). The present study, which was part of a larger effort to document the merits of establishing a large biosphere reserve in the area, confirmed the importance of the prairie dog complex and grasslands to many species of conservation concern, including the threatened mountain plover (Charadrius montanus), a winter resident. With the␣higher-elevation habitats yet to be surveyed, the local diversity of bird species here already places the proposed reserve among the most important protected areas in all of Mexico. The establishment of the reserve is urgently needed, especially for the protection of grasslands and their associated fauna.     

Wild Mushroom Markets in Central Mexico and a Case Study at Ozumba

Wild Mushroom Markets in Central Mexico and a Case Study at Ozumba. More than 200 species of wild edible mushrooms are consumed in Mexico, and over 100 are sold in local, regional, and wholesale markets. This paper analyzes general trends in the commercialization of wild edible mushrooms at twelve markets in central Mexico, where at least 90 species are sold and more than 100 local names were registered. The paper then focuses its analysis on the traditional market at Ozumba (state of Mexico) near Izta-Popo and Zoquiapan national parks. In 2006, 411 stands selling more than 60 mushroom species were sampled throughout the year to record information on the vendors and the species they sold. The greatest diversity of species was recorded in July and August. More than 90% of the wild mushroom vendors were women, and 64% were 40 to 60 years old. The economic value of wild mushrooms in some regions of Mexico appears to contribute to the maintenance of traditional ethnobiological knowledge, generally observed to be in overall decline.     

Media framing of the Cayman Turtle Farm: Implications for conservation conflicts

Conflicts over natural resource use and management often arise where groups have different goals or priorities. The media can play an important dual role in these conflicts; article content might offer insights about public opinion, whilst media may shape debates and how issues are perceived by the public and decision-makers. Wildlife farming is a contentious conservation tool attracting the attention of worldwide media, and associated conflicts among different interest groups may undermine its applicability. We investigated the media’s portrayal of the Cayman Turtle Farm (CTF), a facility in the Cayman Islands which breeds green sea turtles (Chelonia mydas) for human consumption, to investigate how the media presents information about wildlife farming (i.e. framing), consider its potential roles influencing conflicts and explore how it can be used for conservation conflict management. Content analysis was used to compare framing, article valence, and stakeholder representation in 634 newspaper articles from the international and local media. These media stories were framed in terms of: tourism, conflict, conservation, culture/community, management, and utilisation. International articles most often described CTF as a tourism facility. However, during a media campaign by an international animal welfare group, CTF was also often depicted as a source of controversy. Trade in turtle products was mostly debated in older articles. Local media mainly had a financial focus. Conflict framing was associated with a negative article valence, and conflict framed articles were significantly more likely to contain no conservation information. Mentions of environmental interest groups were significantly associated with negative articles, whereas academics were significantly more likely to be mentioned in positive articles. Conservationists must consider stakeholder objectives from the outset of interventions and be aware of the multiple roles the media might play. Media analysis and effectively harnessing the potential of media outlets should be considered as tools for managing conservation conflicts.     

Potential distribution of Ursus americanus in Mexico and its persistence: Implications for conservation

The black bear Ursus americanus is an endangered species in Mexico. Its historical distribution has decreased by approximately 80% although its current distribution is not known with precision; it is only reported to be present in the mountains of Northern Mexico. This study proposes two ensemble models: Mexicós black bear (a) potential distribution compared with Natural Protected Areas (NPAs); and, (b) persistence areas for 2024. The current distribution variables are coniferous forest, elevation and dry forest. Suitable habitat for black bear (354,047 km², 18.07% of the country) was found mainly in the north of the Sonoran biogeographical zone, along the Sierra Madre Occidental, the center and south of the Sierra Madre Oriental and some northern regions of the Altiplano Norte. Comparing these areas with NPAs documented that only 12.41% of potential distribution coincided with current suitable habitat. There are unprotected areas in Sierra Madre Occidental center and central and southern of Sierra Madre Oriental. The model for 2024 indicates a reduction of suitable habitat of 64.5%, mainly in the northern Sonoran zone and the center Sierra Madre Occidental. On the other hand, areas that will persist (125,673 km²) are located along the two main mountain ranges of Mexico. Identification of these sites will allow strengthening of long-term conservation strategies.     

Feasibility for the establishing a carrageenan industry in Mexico

Mexico has been an exporter of carrageenophytes for the last 30 years, but to date there is no commercial production of carrageenan. In the last 10 years the carrageenan consumption in Mexico has increased significantly. During this same period, an increasing number of studies related to carrageenophytes and their industrialization in Mexico have been performed. In this paper, the feasibility of a carrageenan industry in Mexico is analyzed utilizing available information. Future necessary research is suggested where data is lacking. The analysis includes the availability of seaweed biomass, carrageenan types, extraction technology, national demand and possibilities of joint ventures under the NAFTA treaty.     

Primates as pets in Mexico City: an assessment of the species involved, source of origin, and general aspects of treatment

The large human populations in cities are an important source of demand for wildlife pets, including primates, and not much is known about the primate species involved in terms of their general origin, the length of time they are kept as pets, and some of the maintenance problems encountered with their use as pets. We report the results of a survey conducted in Mexico City among primate pet owners, which was aimed at providing some of the above information. We used an ethnographic approach, and pet owners were treated as informants to gain their trust so that we could enter their homes and learn about the life of their primate pets. We surveyed 179 owners of primate pets, which included 12 primate species. Of these, three were native species (Ateles geoffroyi, Alouatta pigra, and A. palliata). The rest were other neotropical primate species not native to Mexico, and some paleotropical species. Spider monkeys and two species of howler monkeys native to Mexico accounted for 67% and 15%, respectively, of the primate cases investigated. The most expensive primate pets were those imported from abroad, while the least expensive were the Mexican species. About 45% of the native primate pets were obtained by their owners in a large market in Mexico City, and the rest were obtained in southern Mexico. Although they can provide companionship for children and adults, primate pets are subject to a number of hazards, some of which put their lives at risk. The demand by city dwellers for primate pets, along with habitat destruction and fragmentation, exerts a significant pressure on wild populations in southern Mexico.     

The Collection and Sale of Wild Mushrooms in a Community of Tlaxcala,Mexico

The Collection and Sale of Wild Mushrooms in a Community of Tlaxcala, Mexico. In this paper, we characterize the harvest and sale of wild mushrooms in Javier Mina (Tlaxcala state, Mexico) based on observations made during visits to that community during the rainy seasons of 1995 and 2001. While there, we visited the forests with various families of mushroom gatherers and also carried out 16 visits to a local mushroom broker to obtain information on the buying and selling of the mushrooms, including a list of the prices per kilo of the species that are sold commercially. Boletus cf. pinophilus, Lyophyllum cf. decastes, Hebeloma aff. mesophaeum and the Amanita caesarea complex were the highest–priced species, and were those collected in the greatest amounts. Our observations indicate that the gathering of mushrooms, a traditional activity among the people of Javier Mina, contributes, through the sale of the mushrooms, to the income of the community during the rainy season.

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Recolección y venta de hongos silvestres en una comunidad de Tlaxcala, México. Recolección y venta de hongos silvestres en una comunidad de Tlaxcala, México. El objetivo de este trabajo es describir el proceso de recolección y venta de hongos silvestres en Javier Mina, Tlaxcala. Para describir estas actividades se realizaron visitas a los bosques con varias familias recolectoras de hongos durante las épocas de lluvias de 1995 y 2001. Además, se realizaron 16 visitas a un distribuidor local para registrar información con respecto a la compra y venta de los hongos. Se obtuvo un listado de los precios por kilo de los hongos que se comercializan. Boletus cf. pinophilus, Lyophyllum cf. decastes, Hebeloma aff. mesophaeum y Amanita caesarea complex fueron los hongos recolectados en mayor cantidad durante este estudio, mismos que tuvieron los precios más altos de compra–venta. Se concluye que la recolección de hongos es una actividad tradicional para la gente de Javier Mina; sin embargo, la venta de éstos, contribuye a la obtención de ingresos durante la temporada de lluvias.

     

Demography of the cycad Ceratozamia mirandae (Zamiaceae) under disturbed and undisturbed conditions in a biosphere reserve of Mexico

The cycad Ceratozamia mirandae is endemic to Chiapas, Mexico. Demographic studies were made in two of its populations in the Sepultura Biosphere Reserve under different conservation conditions; in the nucleus zone “Tres Picos” (conserved) and buffer zone “La Sombra” (disturbed and under management). Spatial distribution of C. mirandae was aggregated, showed a clumped local distribution on shallow soils on steep slopes and male and female cones appear to be synchronous in both populations. The population structure was of type I (Bongers) for both sites. Individuals between the sites showed differences in growth pattern. The oldest plants (80–90 cm tall) were estimated to be about 490 years at “La Sombra”. The finite growth rate () in the buffer zone population showed a tendency for decrease whilst in the nucleus zone this estimate remained stable. The highest elasticity values lied in the transition of the first three classes of the “La Sombra” population, in “Tres Picos” this corresponded to adult plants between 20 and 30 cm tall. Given the above, it is proposed that in the nucleus zone, reproductive adults should be of highest conservation priority, whereas in the buffer zone seedling reintroduction should be carried out regularly until the population increases. We recommend an IUCN Red List category of Vulnerable (VU C, 2a), largely due to difficult-to-control destructive annual forest fires that occur in this Reserve.     

The use of habitat and time by lizards in a tropical deciduous forest in western Mexico

Ecological studies on seasonally dry tropical forest herpetofauna are scarce and those focused on interspecific relations of lizards in this endangered ecosystem are even fewer. This study evaluates general and seasonal patterns in time and habitat use among four lizard species (Anolis nebulosus, Sceloporus melanorhinus, S. utiformis, and Urosaurus bicarinatus) in a protected area of dry tropical forest in western Mexico. Data were gathered by visual surveys along 12 linear parallel transects located in an undisturbed habitat. Anolis nebulosus showed a bimodal pattern in daily activity whereas the other species exhibited unimodal patterns of activity. Seasonality only affected the general activity patterns of S. melanorhinus and U. bicarinatus. With the exception of A. nebulosus and S. melanorhinus, statistical differences were found for all pairwise comparisons of general and seasonal patterns of habitat use. The use of leaf‐litter and low perches in arboreal species was higher during the dry season, probably in response to higher food availability in these habitats. As expected, environmental seasonality affects both activity time and habitat use by lizards. Results suggest greater differences in habitat use than in time of activity among species. The data also indicate complementary use of time and space by these lizard species: species showing similar activity patterns exhibit greater differences in their habitat use. Predation could be an important factor affecting the use of habitat and time by the four lizard species.

Los estudios ecológicos de la herpetofauna de los bosques tropicales secos son escasos y aquellos enfocados a las relaciones ínterespecíficas en lagartijas de este ecosistema fuertemente amenazado son aún más raros. Este estudio evalúa el uso del tiempo y del hábitat de cuatro especies de lagartijas (Anolis nebulosus, Sceloporus melanorhinus, S. utiformis y, Urosaurus bicarinatus) en un área protegida en el occidente de México al comparar los patrones generales y estacionales. La información se obtuvo basándose en 12 transectos visuales ubicados en bosque intacto. Anolis nebulosus registró un patrón bimodal de actividad diaria mientras que en el resto fue unimodal, pero aparentemente, la estacionalidad solo afecto los patrones generales de S. melanorhinus y U. bicarinatus. A excepción de A. nebulosus y S. melanorhinus, todas las comparaciones intraespecificas de los patrones generales y estacionales del uso del hábitat mostraron diferencias estadísticamente significativas. El uso de la hojarasca y perchas mas bajas, en las especies arborícolas, fue mayor durante la época de sequía probablemente en respuesta a una mayor disponibilidad de alimento en esos hábitats durante ese tiempo. Como se esperaba, la estacionalidad puede afectar el uso del tiempo y hábitat en lagartijas. Los resultados sugieren la posibilidad de un mayor uso diferencial del hábitat que del tiempo y la ocurrencia de un uso complementario de ellos: las especies con patrones de actividad más similares difieren más en su uso del hábitat. La depredación puede tener un efecto importante en el uso del tiempo y hábitat de estas especies de lagartijas.     

Middle-class residential mobility in Mexico City: Toward a cross-cultural theory

Few social-psychological theories of intraurban residential mobility have been offered, despite a number of empirical studies of personal motives. A complete explanation of residential mobility would interrelate macroscopic economic factors with household preferences. A cross-cultural socio-psychological model is presented as a step toward a comprehensive theory. Data from an exploratory study of middle-class Mexico City residents are used to test the model. Results suggest that middle-class Mexicans decide to move because of space needs accompanying life-cycle changes, desire for home ownership, and environmental reasons. Home selection was primarily a function of availability, cost, and terms. Unlike North Americans, suburban Mexicans were uninterested in community activities and maintained close contact with relatives; central-city respondents enjoyed living in the city despite dissatisfaction with residence or neighborhood. Most would avoid the suburbs because of communication problems and distance from relatives. Results support the model and justify further testing and development.I am grateful to the University of Alabama Research Grants Committee and Center for International Studies for financial support to carry out this study.An earlier version of this paper was presented at the annual meeting of the American Sociological Society in New York, August 1976.     

Jellyfish on the Rocks: Bioinvasion Threat of the International Trade in Aquarium Live Rock

So-called “live rock” – coral rock that harbours a vast array of marine organisms that enhance the aesthetics and function of aquariums – is an increasingly valuable commodity in the aquarium industry. Live rock is primarily collected from the edges of reefs in the Indo-Pacific, where its export is an important source of revenue for many small subsistence communities. The trade in live rock is not subject to quarantine restrictions in its principal markets, yet poses a serious threat of bioinvasion because of the potential for inadvertent or deliberate release of the organisms that reside on its surfaces. This threat is demonstrated here by the transportation of jellyfish polyps of a species of Cassiopea (Upside-down jellyfish) on live rock imported to the USA from the Indo-Pacific. Jellyfish have recently come into the spotlight as significant bioinvaders. The transportation of jellyfish on live rock provides the first direct evidence of a translocation vector for these organisms. Invasive species are a principal threat to biodiversity and are responsible for enormous economic losses globally. The unregulated trade in live rock presents a serious bioinvasion risk that warrants the urgent attention of regulatory bodies.     

Indigenous Medicinal Plants in Mexico: the Example of the Nahua (Sierra de Zongolica)

As in most peasant cultures medicinal plants are a very important resource for the Nahua of the Sierra de Zongolica (Mexico). Documentation of the current indigenous medicinal uses of 203 plants in this region was conducted during 18 months of fieldwork. The 816 individual reports documented were divided into nine groups of indigenous uses. The frequency of usage of the individual plants reported was employed in the analysis of the ethnobotanical importance of the respective plants. Plants cited more frequently in a group of indigenous uses are regarded as of greater ethnobotanical importance than those cited only by a few informants. Data on phytochemistry, pharmacology and ethnobotany from the scientific literature were used to evaluate possible biological or pharmacological and toxicological effects of some particularly important plants. For most plants detailed studies on these actions are still lacking, which would allow a conclusive evaluation. This ethnobotanical evaluation forms the basis for such studies which have been started on some plants, and for better understanding their potential as minor economic products of the region. These uses may also give incentives to the conservation of the local biodiversity.     

The Three-Dimensional Human Skin Reconstruct Model: a Tool to Study Normal Skin and Melanoma Progression

Most in vitro studies in experimental skin biology have been done in 2-dimensional (2D) monocultures, while accumulating evidence suggests that cells behave differently when they are grown within a 3D extra-cellular matrix and also interact with other cells (1-5). Mouse models have been broadly utilized to study tissue morphogenesis in vivo. However mouse and human skin have significant differences in cellular architecture and physiology, which makes it difficult to extrapolate mouse studies to humans. Since melanocytes in mouse skin are mostly localized in hair follicles, they have distinct biological properties from those of humans, which locate primarily at the basal layer of the epidermis. The recent development of 3D human skin reconstruct models has enabled the field to investigate cell-matrix and cell-cell interactions between different cell types. The reconstructs consist of a "dermis" with fibroblasts embedded in a collagen I matrix, an "epidermis", which is comprised of stratified, differentiated keratinocytes and a functional basement membrane, which separates epidermis from dermis. Collagen provides scaffolding, nutrient delivery, and potential for cell-to-cell interaction. The 3D skin models incorporating melanocytic cells recapitulate natural features of melanocyte homeostasis and melanoma progression in human skin. As in vivo, melanocytes in reconstructed skin are localized at the basement membrane interspersed with basal layer keratinocytes. Melanoma cells exhibit the same characteristics reflecting the original tumor stage (RGP, VGP and metastatic melanoma cells) in vivo. Recently, dermal stem cells have been identified in the human dermis (6). These multi-potent stem cells can migrate to the epidermis and differentiate to melanocytes.