Primate

About: Primate is a research topic. Over the lifetime, 1250 publications have been published within this topic receiving 67388 citations. The topic is also known as: the primate order & primates.

The neonatal marmoset monkey ovary is very primitive exhibiting many oogonia

Abstract: Oogonia are characterized by diploidy and mitotic proliferation. Human and mouse oogonia express several factors such as OCT4, which are characteristic of pluripotent cells. In human, almost all oogonia enter meiosis between weeks 9 and 22 of prenatal development or undergo mitotic arrest and subsequent elimination from the ovary. As a consequence, neonatal human ovaries generally lack oogonia. The same was found in neonatal ovaries of the rhesus monkey, a representative of the old world monkeys (Catarrhini). By contrast, proliferating oogonia were found in adult prosimians (now called Strepsirrhini), which is a group of 'lower' primates. The common marmoset monkey (Callithrix jacchus) belongs to the new world monkeys (Platyrrhini) and is increasingly used in reproductive biology and stem cell research. However, ovarian development in the marmoset monkey has not been widely investigated. Herein, we show that the neonatal marmoset ovary has an extremely immature histological appearance compared with the human ovary. It contains numerous oogonia expressing the pluripotency factors OCT4A, SALL4, and LIN28A (LIN28). The pluripotency factor-positive germ cells also express the proliferation marker MKI67 (Ki-67), which has previously been shown in the human ovary to be restricted to premeiotic germ cells. Together, the data demonstrate the primitiveness of the neonatal marmoset ovary compared with human. This study may introduce the marmoset monkey as a non-human primate model to experimentally study the aspects of primate primitive gonad development, follicle assembly, and germ cell biology in vivo.

Recognition Memory in Marmoset and Macaque Monkeys: A Comparison of Active Vision.

Abstract: The core functional organization of the primate brain is remarkably conserved across the order, but behavioral differences evident between species likely reflect derived modifications in the underlying neural processes. Here, we performed the first study to directly compare visual recognition memory in two primate species-rhesus macaques and marmoset monkeys-on the same visual preferential looking task as a first step toward identifying similarities and differences in this cognitive process across the primate phylogeny. Preferences in looking behavior on the task were broadly similar between the species, with greater looking times for novel images compared with repeated images as well as a similarly strong preference for faces compared with other categories. Unexpectedly, we found large behavioral differences among the two species in looking behavior independent of image familiarity. Marmosets exhibited longer looking times, with greater variability compared with macaques, regardless of image content or familiarity. Perhaps most strikingly, marmosets shifted their gaze across the images more quickly, suggesting a different behavioral strategy when viewing images. Although such differences limit the comparison of recognition memory across these closely related species, they point to interesting differences in the mechanisms underlying active vision that have significant implications for future neurobiological investigations with these two nonhuman primate species. Elucidating whether these patterns are reflective of species or broader phylogenetic differences (e.g., between New World and Old World monkeys) necessitates a broader sample of primate taxa from across the Order.

Implications of Enamel Prism Patterns for the Origin of the New World Monkeys

Abstract: The origin and dispersal of the New World monkeys to the South American continent present an interesting dilemma, for paleogeographical evidence indicates that South America had already separated from Africa by the end of the Cretaceous. During the Tertiary, South America remained an island continent isolated from the rest of the world by oceanic barriers, from the Middle Paleocene [ca. 55 million years (m.y.) ago] to the Middle Pliocene (ca. 3.5 m.y. ago) (Hershkovitz, 1977; Hoffsteffer, 1972, 1974; Orlosky and Swindler, 1975). The source of origin of the New World monkeys both from a biogeographic and a phylogenetic perspective is thus uncertain and controversial. Two main hypotheses have been proposed: 1. The Platyrrhini as well as the Catarrhini were independently derived from Laurasian Paleogene primates, presumably an omomyid lower primate. Therefore, the close resemblance of New and Old World monkeys can be interpreted or explained as a result of convergence and/or parallelism from a lower primate ancestor. 2. The Platyrrhini and the Catarrhini were derived from a common ancestral anthropoid stock probably African in origin with the dispersal of the platyrrhine ancestors occurring through direct faunal interchange (rafting) between the southern continents across the South Atlantic Ocean.

Enteric infections in chimpanzees and spider monkeys with special reference to a sulfadiazine resistant Shigella.

Abstract: In a report on the progress in the study of bacillary dysentery, Weil1 states that the only naturally susceptible animal to bacillary dysentery is the monkey. The rhesus monkey is not only a known carrier of Shigella, but also developes an acute disease clinically and pathologically comparable to that in man.2 Janeta and Dack3 observed that susceptibility in monkeys was greatly increased by a deficiency in Vitamin M, enhancing the value of these animals in the study of experimental bacillary dysentery. Although a search of the literature fails to reveal any previous reports of Shigella or Salmonella infections in chimpanzees, it seems probable that all higher primates are susceptible. This report is concerned with the types of enteric organisms isolated since 1942 from the colony of chimpanzees and monkeys at the Yerkes Laboratories of Primate Biology, Orange Park, Florida, by the State Board of Health Laboratory in Jacksonville. The clinical

Tool use in wild spider monkeys ( Ateles geoffroyi )

Abstract: Tool use has been observed in a variety of primate species, including both New and Old World monkeys. However, such reports mainly address the most prodigious tool users and frequently limit discussions of tool-using behavior to a foraging framework. Here, we present observations of novel and spontaneous tool use in wild black-handed spider monkeys (Ateles geoffroyi), where female spider monkeys used detached sticks in a self-directed manner. We introduce factors to explain Ateles tool-using abilities and limitations, and encourage the synthesis of relevant research in order to gain insight into the cognitive abilities of spider monkeys and the evolution of tool-using behaviors in primates.