Research Progress on Developmental Biology of Sarcosaprophagous Insects / 法医学杂志

Forensic entomology provides a feasible way to estimate postmortem interval (PMI), of which the growth and development of sarcosaprophagous insects is the most widely used indicator in forensic practice. Over the years, forensic entomologists have carried out a large number of studies on the development biology of sarcosaprophagous insects. This paper illustrates the main factors that affect the development of sarcosaprophagous insects, including temperature, humidity, light, food types and poisons. The development indicators of sarcosaprophagous insects were reviewed from the perspectives of morphology, differential gene expression and biochemical characteristics. It is emphasized that future research of development biology on sarcosaprophagous insects should fully absorb and integrate the methods of artificial intelligence and omics, and the research object also needs further expansion in order to establish a more objective and more accurate PMI estimation method.

Morfometría geométrica y sus nuevas aplicaciones en ecología y biología evolutiva: Parte 2 / Geometric morphometric and its new applications in ecology and evolutionary biology: Part 2

RESUMEN: La presente revisión entrega una visión actualizada del estudio de la morfometría geométrica y sus aplicaciones más actuales en ecología y biología evolutiva, metodología con una amplia variación en los últimos 5 años de su primera versión en International Journal of Morphology. La Morfometría geométrica es una herramienta que permite evaluar las variaciones morfológicas con factores subyacentes, siendo una herramienta más sensible que la morfometría tradicional, lo que permite detectar mínimos cambios de variación morfológica. Lo que la ha vuelto una herramienta notable para responder preguntas de biología comparada centradas en caracteres anatómicos. En sus comienzos fue una herramienta usada principalmente para responder preguntas taxonómicas, y para diferenciar a nivel de individuos, poblaciones o especies. No obstante, en los últimos años la cantidad de preguntas y problemáticas en las que se aplica, ha diversificado considerablemente, pasando a ser una herramienta muy precisa para responder preguntas de variación morfológica en contextos ecológicos y evolutivos. Ya ha pasado casi media década desde la última revisión del método, por lo que éste trabajo tiene como objetivo analizar los cambios metodológicos y los nuevos enfoques usados en Morfometría geométrica, y presentar una pequeña guía introductoria a éstos nuevos métodos, sus usos y aplicaciones.

SUMMARY: This study provides an updated vision of the study of Geometric Morphometrics and its most recent application in ecology and evolutionary biology, covering a wide variation in methodology occurring in the last 5 years since the first version published in the International Journal of Morphology. Geometric Morphometrics is a tool that allows evaluating morphological variations with underlying factors, with a higher sensitivity than traditional morphology, so that minimum changes of morphological variation can be detected. Therefore, it has turned into an outstanding tool to answer questions of comparative biology focused on anatomic characters. At the beginning, it was a tool mainly used to answer taxonomic questions and for differentiation at individual, population or species level. However, in the last years, the number of questions and problematic on which it is applied, has diversified considerably, turning it into a very accurate tool to answer questions of morphological variation in ecologic and evolutionary contexts. Almost half a decade has elapsed since the last revision of the method, so this work is intended to analyze the methodological changes and the new approaches used in Geometric Morphometrics, including a brief introductory guideline to these new methods, their uses and applications.

Para além da concepção binária cis-heternormativa: a psicanálise interrogada pelas diversidades sexuais e de gênero / Beyond the binary and cis-heteronormative conception: psychoanalysis interrogated by sexual and gender diversities / Mas allá de la concepción binaria cisheternormativa: el psicoanálisis interrogado por la diversidade sexual y de género

Freud debruçou-se, ao longo de toda sua incansável produção teórica, sobre a complexidade da sexualidade humana e seus desdobramentos. A partir da experiência da fundação do "Laboratório de Sexualidade, Gênero e Psicanálise" no Serviço de Atendimento e Pesquisa em Psicologia (SAPP) - Serviço-Escola do Curso de Psicologia da Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS) - pretende-se, neste artigo produzir tensionamentos teóricos a respeito dos paradigmas metapsicológicos que, por muito tempo, sustentaram o pensamento psicanalítico. Revela-se o grande impacto do reconhecimento da falta teórica e técnica da Psicanálise, que sustentada historicamente por uma lógica binaria e cis-heteronormativa, não pôde dar conta de compreender as múltiplas formas de exercício da sexualidade. Por outro lado, entende-se que a (re)construção de normas faz da Psicanálise um instrumento vigoroso na escuta de modos de sexualidade e produção de subjetividades. Apoiado em constructos fundamentais, este trabalho propõe-se seguir com a sustentação metapsicológica da alteridade como acesso ao estatuto das diferenças nas relações do Eu e com os outros.(AU)

Throughout his tireless theoretical production, Freud looked at the complexity of human sexuality and its development. From the experience of founding the "Laboratório de Sexualidade, Gênero e Psicanálise" at the Psychological Care and Research Service at the Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS) - this essay is intended to produce theoretical tensions regarding the metapsychological paradigms that for a long time sustained psychoanalytic thought. It reveals the great impact of the recognition of the psychoanalysis theoretical and technical lack, which, historically supported by a binary and cis-heteronormative logic, could not account for understanding the multiple forms of the exercise of sexuality. On the other hand, it is understood that the (re)construction of norms makes Psychoanalysis a powerful instrument in listening to modes of sexuality and production of subjectivities. Based on fundamental constructs, it is proposed to follow with the metapsychological support of alterity as access to the status of differences in self-relationships and with others.(AU)

Freud se inclinó, a lo largo de toda su incansable producción teórica, sobre la complejidad de la sexualidad humana y sus desdoblamientos. A partir de la experiencia de la fundación del "Laboratorio de Sexualidad, Género y Psicoanálisis" en el Servicio de Atención e Investigación en Psicología (SAPP) - Servicio-Escuela del Grado en Psicología de la Pontificia Universidad Católica del Rio Grande do Sul (PUCRS) - en este artículo se busca producir tensiones teóricas respecto de los paradigmas metapsicológicos que, por mucho tiempo, sostuvieron el pensamiento psicoanalítico. Se revela el gran impacto del reconocimiento de la falta teórica y técnica del Psicoanálisis, que sostenida históricamente por una lógica binaria y cisheteronormativa, no pudo contemplar la comprensión de las múltiples formas de ejercicio de la sexualidad. Por otro lado, se entiende que la (re)construcción de normas hace del Psicoanálisis un instrumento vigoroso en la escucha de modos de sexualidad y producción de subjetividades. Apoyado en constructos fundamentales, este trabajo se propone seguir con la sustentación metapsicológica de la alteridad como acceso al estatuto de las diferencias en las relaciones del Yo y con los demás.(AU)

Origens do(s) sexo(s) e a rainha dos problemas da biologia evolutiva / Origins of sex(es) and the queen of problems of evolutionary biology

A reprodução sexuada já foi considerada universal, e posteriormente, a forma mais perfeita de reprodução. Todavia, a partir de meados do século XIX, pesquisas no nível celular colocaram em xeque a ideia de que tipos de reprodução assexuadas fossem primitivos ou inferiores. Ao longo do século XX, e adentrando no XXI, hipóteses foram levantadas para explicar as vantagens da reprodução sexuada sobre a assexuada assim como o que permitiria a reprodução sexuada se manter quando seria mais vantajoso se reproduzir de forma assexuada. A mais importante e conhecida é a hipótese da Rainha Vermelha. Paralelamente, vários trabalhos procuraram entrever as pressões ecológicas que permitiram e favoreceram o aparecimento da reprodução sexuada em um cenário situado há cerca de dois bilhões de anos. O objetivo desse trabalho é revisar respostas históricas que marcaram o estudo da origem, da evolução e da manutenção da reprodução sexuada, identificando algumas das principais questões que a comunidade científica elaborou nos últimos duzentos anos.

Sexual reproduction has already been considered universal, and subsequently, the most perfect form of reproduction. However, since the mid-nineteenth century, research at the cellular level has questioned the idea that asexual reproduction types are primitive or inferior. During the twentieth century, and entering the XXI, hypotheses were raised to explain the advantages of sexual reproduction over the asexual as well as what would allow sexual reproduction to be maintained when it would be more advantageous to reproduce asexually. The most important and known is the Red Queen hypothesis. At the same time, several studies have sought to understand the ecological pressures that allowed and favored the appearance of sexual reproduction in a scenario that was around two billion years ago. The aim of this work is to review historical responses that marked the study of the origin, evolution and maintenance of sexual reproduction, identifying some of the main questions that the scientific community has elaborated over the last two hundred years.

Evaluación del crecimiento y desarrollo de pacientes con síndrome Down en Santiago de Cuba / Evaluation of growth and development of patients with Down syndrome in Santiago de Cuba

Se realizó un estudio descriptivo, transversal y cuantitativo de 54 pacientes con síndrome de Down, atendidos en la consulta de Genética Clínica del Hospital Pediátrico Sur Docente Dr Antonio María Béguez César de Santiago de Cuba, desde el 2000 hasta el 2015, con el objetivo de determinar el patrón de crecimiento de los afectados. Entre las variables analizadas figuraron la edad, el sexo y los índices antropométricos: peso para la edad, talla para la edad, índice peso/talla e índice de masa corporal; asimismo, se evaluaron los defectos congénitos más frecuentes en la muestra. Se concluye que el patrón de crecimiento de dichos pacientes es similar al descrito en la bibliografía médica relacionada con el tema, lo cual puede ser útil para la atención clínica que se les debe brindar, así como también para orientar a los padres sobre los hábitos alimentarios y estilos de vida como parte del tratamiento de los niños y adolescentes con este síndrome

A descriptive, cross-sectional and quantitative study of 54 patients with Down syndrome, assisted in the Clinical Genetics Service of Dr Antonio María Béguez César Teaching Southern Children Hospital was carried out in Santiago de Cuba, from 2000 to 2015, aimed at determining the growth pattern of those affected patients. Among the analyzed variables there were age, sex and anthropometric indexes: weight according to age, height according to age, weight/height index and body mass index; also, the most frequent congenital defects were evaluated in the sample. It was concluded that the growth pattern of these patients is similar to the one described in the medical literature related to the topic, which can be useful for the clinical care that should be offered, as well as to guide the parents on the eating habits and lifestyles as part of the treatment of children and adolescents with this syndrome

Bioactive Compounds for the Treatment of Renal Disease

Kidney diseases including acute kidney injury and chronic kidney disease are among the largest health issues worldwide. Dialysis and kidney transplantation can replace a significant portion of renal function, however these treatments still have limitations. To overcome these shortcomings, a variety of innovative efforts have been introduced, including cell-based therapies. During the past decades, advances have been made in the stem cell and developmental biology, and tissue engineering. As part of such efforts, studies on renal cell therapy and artificial kidney developments have been conducted, and multiple therapeutic interventions have shown promise in the pre-clinical and clinical settings. More recently, therapeutic cell-secreting secretomes have emerged as a potential alternative to cell-based approaches. This approach involves the use of renotropic factors, such as growth factors and cytokines, that are produced by cells and these factors have shown effectiveness in facilitating kidney function recovery. This review focuses on the renotropic functions of bioactive compounds that provide protective and regenerative effects for kidney tissue repair, based on the available data in the literature.

Comparative study of fertilization rates of C57BL/6NKorl and C57BL/6N mice obtained from two other sources / 한국실험동물학회지

C57BL/6N is the most widely used inbred mouse strain applied in a wide variety of research areas including cancer, cardiovascular biology, developmental biology, diabetes and obesity, genetics, immunology, neurobiology, and sensorineural research. To compare the fertilization rates of C57BL/6NKorl mice with two commercial C57BL/6N stocks, differences in reproductive organ structures, sperm and egg numbers, fertilization rates, and embryo development rates among C57BL/6NKorl (Korea FDA source), C57BL/6NA (USA source), and C57BL/6NB (Japan source) mice were determined. Among the stocks, no significant differences were detected in organ weight and histological structure of male and female reproductive organs, although body weight was higher in C57BL/6NKorl mice than that in the other groups. The concentration and morphology of sperm and eggs in C57BL/6NKorl mice were similar to those of C57BL/6NA and C57BL/6NB mice. Furthermore, the three stocks had similar in vitro fertilization and embryo development rates, although these rates tended to be higher in C57BL/6NB mice. Pup body weight was higher in C57BL/6NKorl and C57BL/6NB mice than that in C57BL/6NA mice. The results of the present study suggest that C57BL/6NKorl, C57BL/6NA, and C57BL/6NB mice obtained from three different sources have similar fertilization and embryo development rates, although there were slight differences in the magnitude of their responses rates.

Skin Pigmentation and Pigmentary Disorders: Focus on Epidermal/Dermal Cross-Talk

Variation in human skin and hair color is the most notable aspect of human variability and several studies in evolution, genetics and developmental biology contributed to explain the mechanisms underlying human skin pigmentation, which is responsible for differences in skin color across the world's populations. Despite skin pigmentation is primarily related to melanocytes functionality, the surrounding keratinocytes and extracellular matrix proteins and fibroblasts in the underlying dermal compartment actively contribute to cutaneous homeostasis. Many autocrine/paracrine secreted factors and cell adhesion mechanisms involving both epidermal and dermal constituents determine constitutive skin pigmentation and, whenever deregulated, the occurrence of pigmentary disorders. In particular, an increased expression of such mediators and their specific receptors frequently lead to hyperpigmentary conditions, such as in melasma and in solar lentigo, whereas a defect in their expression/release is related to hypopigmented disorders, as seen in vitiligo. All these interactions underline the relevant role of pigmentation on human evolution and biology.

Trofoblasto, impronta y conflicto genómico en gineco-obstetricia / Trophoblast, imprinting and genomic conflict in gynecology-obstetrics

La teoría del Conflicto Genómico es parte de la biología evolutiva y actúa en los mamíferos a través del mecanismo de impronta genética, estos genes cumplen un rol central en el desarrollo fetal y del trofoblasto contribuyendo a un balance entre los requerimientos nutricionales fetales (genes con impronta paterna) y el aporte materno (genes con impronta materna). El desbalance de estos genes tiene implicancias en la etiopatogenia de diversas patologías en Gineco-Obstetricia: en Medicina Fetal (preeclampsia, diabetes gestacional, síndrome de Beckwith-Wiedemann), oncología (mola completa, mola incompleta, teratomas) y fertilidad. Se presenta un caso de displasia mesenquimática placentaria asociado a Beckwith-Wiedemann.

The theory of Genomic Conflict is part of evolutionary biology and acts in mammals through the mechanism of genetic imprinting, these genes play a central role in fetal and trophoblastic development producing a balance between fetal nutritional requirements (genes with paternal imprinting) and maternal supply (genes with maternal imprinting). The imbalance of these genes has implications in the pathogenesis of various diseases in Obstetrics and Gynecology: in Fetal Medicine (preeclampsia, gestational diabetes, Beckwith-Wiedemann syndrome), oncology (complete and partial hydatiform mole, teratomas) and fertility. A case of placental mesenchymal dysplasia associated with Beckwith-Wiedemann is presented.

In vitro fertilization (IVF) in mammals: epigenetic and developmental alterations: scientific and bioethical implications for IVF in humans

The advent of in vitro fertilization (IVF) in animals and humans implies an extraordinary change in the environment where the beginning of a new organism takes place. In mammals fertilization occurs in the maternal oviduct, where there are unique conditions for guaranteeing the encounter of the gametes and the first stages of development of the embryo and thus its future. During this period a major epigenetic reprogramming takes place that is crucial for the normal fate of the embryo. This epigenetic reprogramming is very vulnerable to changes in environmental conditions such as the ones implied in IVF, including in vitro culture, nutrition, light, temperature, oxygen tension, embryo-maternal signaling, and the general absence of protection against foreign elements that could affect the stability of this process. The objective of this review is to update the impact of the various conditions inherent in the use of IVF on the epigenetic profile and outcomes of mammalian embryos, including superovulation, IVF technique, embryo culture and manipulation and absence of embryo-maternal signaling. It also covers the possible transgenerational inheritance of the epigenetic alterations associated with assisted reproductive technologies (ART), including its phenotypic consequences as is in the case of the large offspring syndrome (LOS). Finally, the important scientific and bioethical implications of the results found in animals are discussed in terms of the ART in humans.

Desenvolvimento e evolução: paralelismo ou transversalidade? / Development and evolution: parallelism or transversality?

Este ensaio discute as relações entre evolução e desenvolvimento, por meio da identificação de algumas das diferentes acepções de organismo e ambiente que emergiram na Biologia Evolutiva e na Biologia do Desenvolvimento. Inicialmente, duas acepções de organismo são examinadas no contexto do desenvolvimento: uma delas é a pré-formacionista, reeditada na ideia contemporânea de determinismo genético, a outra é epigenética. Verifica-se, em seguida, como os conceitos de organismo subjacentes a essas concepções se articulam com a leitura neodarwinista do processo evolutivo. Uma primeira decorrência dessa análise é que o neodarwinismo subscreve um paralelismo entre desenvolvimento e evolução, a despeito da natureza do processo desenvolvimental em questão. Examina-se,então, uma alternativa a esse quadro presente no paradigma epigenético, que encaminha uma relação transversal entre desenvolvimento e evolução, mediada pela centralidade da experiência ambiental do organismo nessas duas dimensões biológicas. Conclui-se que o paradigma epigenético se encontra em melhor posição de consolidar não só um programa unificante entre as ciências desenvolvimental e evolutiva, como também suscita uma discussão dos valores que permeiam a práxis dessas ciências

This essay discusses the relation ship between evolution and development through the identification of some of the different meanings of organism and environment that emerged in the Evolutionary Biology and Developmental Biology.Initially, two meanings of organism are examined in the developmental context: one of them is the preformationist, reprinted in contemporary idea of genetic determinism, and the other is theepigenetics. It is verified, then, as the concepts of the organism underlying these conceptions arearticulated with the neo-Darwinian interpretation of the evolutionary process. A first result of this analysis is that neo-Darwinism supports a parallel between development and evolution, regardless of the nature of the developmental process in question. Then it examines an alternati ve to that present in the epigeneti c paradigm that forward a tranversal relati onship between developmentand evolution, mediated by the centrality of environmental experience of the organism in these two dimensions biological. It is concluded that the epigenetic paradigm is in a better position to consolidate not only unifying program between developmental and evolutionary sciences but also raises a discussion of the values that permeate the practi ce of these sciences

Síndrome de Down, cerebro y desarrollo / Down syndrome, brain and development

En esta revisión describiremos brevemente los aspectos fundamentales que caracterizan a la Psicología del Desarrollo y a la Neurociencia, como disciplinas científicas necesarias en el estudio y la comprensión del desarrollo ontogenético y sus trastornos. Esto nos permitirá concretar la naturaleza de las distintas etapas del desarrollo, y evaluar los sustratos cerebrales de la conducta asociados a estos cambios evolutivos. Finalmente, expondremos las características neurobiológicas y evolutivas de un trastorno del neurodesarrollo determinado genéticamente, el síndrome de Down.

In this review we briefly describe the main aspects that characterize the Developmental Psychology and Neuroscience as scientific disciplines necessary in the study and understanding of ontogenetic development and it disorders. This allows us to specify the nature of the different stages of development and to evaluate the neural substrates of behavior associated with these evolutionary changes. Finally, we discuss the neurobiological and evolutionary characteristics of a genetically determined neurodevelopmental disorder, the Down syndrome.

Plasticity and reprogramming of differentiated ocular tissue of tadpoles of the frog, Euphlyctis cyanophlyctis under the influence of vitamin A.

Present study has shown that differentiated cell types may loose their definitive characteristics and acquire features of another specialized cell type. Young (3 toe stage) and mature (5 toe stage) tadpoles of the frog, Euphylictis cyanophlyctis were employed as experimental animals. Experiments were completed in two phases: in the first part of experiment, lenses were extracted from right eye balls of tadpoles and treated with vitamin A; in the second part of the experiment, meshed lentectomized eye ball tissues were implanted into the pit made on mid lateral position of the tail of young and mature tadpoles and were treated with vitamin A. The results obtained gave clear evidence of plasticity and reprogramming of terminally differentiated ocular tissue into lens, retina and even complete eye. Vitamin A was found to be good model for accelerating the reprogramming of differentiated ocular tissue in anuran frog tadpoles.

Molecular regulation of kidney development / 대한해부학회지

Genetically engineered mice have provided much information about gene function in the field of developmental biology. Recently, conditional gene targeting using the Cre/loxP system has been developed to control the cell type and timing of the target gene expression. The increase in number of kidney-specific Cre mice allows for the analysis of phenotypes that cannot be addressed by conventional gene targeting. The mammalian kidney is a vital organ that plays a critical homeostatic role in the regulation of body fluid composition and excretion of waste products. The interactions between epithelial and mesenchymal cells are very critical events in the field of developmental biology, especially renal development. Kidney development is a complex process, requiring inductive interactions between epithelial and mesenchymal cells that eventually lead to the growth and differentiation of multiple highly specialized stromal, vascular, and epithelial cell types. Through the use of genetically engineered mouse models, the molecular bases for many of the events in the developing kidney have been identified. Defective morphogenesis may result in clinical phenotypes that range from complete renal agenesis to diseases such as hypertension that exist in the setting of grossly normal kidneys. In this review, we focus on the growth and transcription factors that define kidney progenitor cell populations, initiate ureteric bud branching, induce nephron formation within the metanephric mesenchyme, and differentiate stromal and vascular progenitors in the metanephric mesenchyme.

Estudo histológico da placenta murina com enfoque em seu potencial hematopoético / Histological study of murine placenta with a focus on their potential hematopoietic

As células-tronco hematopoéticas (CTH), encontradas na medula óssea de mamíferos adultos, são formadas durante a embriogênese, em múltiplos locais anatômicos, migrando de um sítio para outro onde são expandidas e diferenciadas até seu estabelecimento definitivo na medula óssea. Recentemente, estudos in vitro têm demonstrado que a placenta possui potencial hematopoético, revelando a presença de progenitores multipotentes e autorrenováveis. Não obstante a importância destes trabalhos, a maioria empregou métodos in vitro, o que não significa que in vivo este potencial se expresse em algum momento. No entanto, há dados que mostraram focos de eritropoese placentária observadas em 10,5 dias-pós-coito (dpc) formando maciços celulares no labirinto que, depois, se configuravam no interior de vasos. Dentro desse cenário, nos propusemos a aprofundar essa questão a partir de um maior detalhamento morfológico in situ de placentas de camundongo em diferentes idades gestacionais, avaliando a efetiva participação da placenta na hematopoese. Para tal, foi feita uma análise histológica da placenta de camundongos Swiss Webster entre 9,5 e 11,5 dpc, através de cortes seriados e da utilização de colorações convencionais e específicas, bem como empregando marcações com anticorpos ou por lectinas conjugadas a FITC. Foi dada ênfase às células sanguíneas encontradas neste período, procurando por possíveis focos de atividade hematopoética, ao mesmo tempo em que se fez necessário uma caracterização morfológica deste órgão, cuja literatura em camundongos é escassa. Células maiores e mais globosas que as células eritróides imaturas oriundas do saco vitelínico foram observadas circulando nos vasos sanguíneos fetais da placenta, sendo que em algumas áreas, tais células não pareciam estar envolvidas por endotélio e pareciam estar aderidas umas às outras. Numerosos brotamentos de células imaturas de morfologia trofoblástica foram observados, exibindo adesões largas ou sob a forma de pedículos de adesão com endotélio e/ou trofoblasto adjacente, com algumas células hemoglobinizadas. Ainda, em algumas áreas, foram observados conjuntos de células eritróides de aspecto trofoblástico formando aglomerados diferenciais em meio à massa trofoblástica, com células aderidas e com diferentes graus de hemoglobinização. Esses achados encontravam-se principalmente à região de labirinto próxima às células trofoblásticas gigantes e espongiotrofoblasto. Aglomerados hematopoéticos semelhantes aos brotamentos de CTH da região de aorta-gônadas-mesonefros (AGM) e vasos umbilicais e vitelínicos também foram encontrados próximos à face fetal da placenta. A imunomarcação revelou a presença de eritropoietina na decídua, a qual pode ter então papel importante na indução da eritropoese encontrada, bem como de fator de von Willebrand em células que se projetavam para dentro da circulação fetal. Ainda, células de aspecto trofoblástico no interior dos vasos fetais foram Sca-1 positivas. A utilização de lectinas permitiu caracterizar, ao menos parcialmente, os resíduos de açúcar presentes nos diferentes endotélios e na barreira materno-fetal. Em conclusão, os resultados do presente estudo trazem contribuições originais ao estudo morfológico da placenta na metade da gestação, contribuindo para a compreensão da participação da placenta na ontogenia do sistema hematopoético em mamíferos.

Stem cells in the light of evolution.

All organisms depend on stem cells for their survival. As a result, stem cells may be a prerequisite for the evolution of specific characteristics in organisms that include regeneration, multicellularity and coloniality. Stem cells have attracted the attention of biologists and medical scientists for a long time. These provide materials for regenerative medicine. We review in this paper, the link between modern stem cell research and early studies in ancient organisms. It also outlines details on stem cells in the light of evolution with an emphasis on their regeneration potential, coloniality and multicellularity. The information provided might be of use to molecular biologists, medical scientists and developmental biologists who are engaged in integrated research involving the stem cells.

Progress in research on the biological reason of male homosexuality / 中华医学遗传学杂志

Male homosexuality is a complex phenomenon which is universal and with unknown causes. Researchers believe that both biological and environmental factors have played a role in its pathogenesis. Researches focusing on genetics, neurobiology, development and endocrinology have made certain progress. In this paper, we have reviewed the biological causes of male homosexuality, which may provide clues for further research in this field.