Characterization of Satellite DNAs in Squirrel Monkeys genus Saimiri (Cebidae, Platyrrhini)

Abstract

the genus Saimiri is a decades-long taxonomic and phylogenetic puzzle to which cytogenetics has contributed crucial data. All Saimiri species apparently have a diploid number of 2n = 44 but vary in the number of chromosome arms. Repetitive sequences such as satellite DnAs are potentially informative cytogenetic markers because they display high evolutionary rates. our goal is to increase the pertinent karyological data by more fully characterizing satellite DnA sequences in the Saimiri genus. We were able to identify two abundant satellite DNAs, alpha (~340 bp) and CapA (~1,500 bp), from short-read clustering of sequencing datasets from S. boliviensis. The alpha sequences comprise about 1% and the CapA 2.2% of the S. boliviensis genome. We also mapped both satellite DnAs in S. boliviensis, S. sciureus, S. vanzolinii, and S. ustus. The alpha has high interspecific repeat homogeneity and was mapped to the centromeres of all analyzed species. capA is associated with non-pericentromeric heterochromatin and its distribution varies among Saimiri species. We conclude that capA genomic distribution and its pervasiveness across platyrrhini makes it an attractive cytogenetic marker for Saimiri and other new World monkeys. Squirrel monkeys of the genus Saimiri (Cebidae, Platyrrhini) are medium sized neotropical primates inhabiting forest environments of South America. They range from about 10°N to 17°S including the Amazon basin, the Guianas, and coastal zones of Central America 1,2. As for many other New World monkey (NWM) taxa the phylogenetic relationships within the genus Saimiri are still debated 3. Even the number of species is uncertain, historically ranging from one to 16 distinguished species 4-11. In a recent molecular report on mitochondrial D-Loop and cyt b sequences, Alfaro et al. 3 presented a provisional taxonomy of seven Saimiri species and various subspecies: (1) S. boliviensis, (2) S.

Satellite DNAs—From Localized to Highly Dispersed Genome Components

“…Not only a substantial number of (even low-copy) repetitive sequences can be detected by satellitome analysis, as exampled by 164 satDNAs of Megaleporinus macrocephalus [ 106 ], but such studies can also help in elucidating evolutionary relations among repetitive sequences in related species [ 94 , 119 , 121 , 124 , 126 , 133 , 134 , 135 , 136 , 137 , 138 , 139 ]. The use of NGS data has also been employed for the studies of evolution of B and sex chromosomes, e.g., to characterize the composition and putative ancestry of B chromosomes in grasshopper species Rhammatocerus brasiliensis , Schistocerca rubiginosa, Xyleus discoideus angulatus, Abracris flavolineata, Eumigus monticola [ 93 , 102 , 112 ] or in characid fish Characidium gomesi [ 96 ].…”

First Description of a Satellite DNA in Manatees’ Centromeric Regions

“…This process, which has been described for many satDNAs, promotes fast sequence homogenization within a species or population, resulting in much higher interspecific than intraspecific differences (Plohl et al, 2012). Although interspecific satDNA sequence conservation is unexpected according to the concerted evolution model, interspecific homogeneity of centromeric satDNAs was observed in other mammalian groups, like in rodents from the Peromyscus genus (Smalec et al, 2019), in four squirrel monkeys (Saimiri genus; Valeri et al, 2020) and in two species of two-toed sloths from the genus Choloepus (Sena et al, 2020). In all these cases, a possible centromeric function was hypothesized.…”

“…Fluorescent in situ hybridization (FISH) was performed using the TMAsat cloned (MW272776) sequence as probe on metaphase spreads of T. manatus and T. inunguis. FISH was performed with 200 ng of biotin-labelled probes, following (Valeri et al, 2020). The analyses and image acquisition were performed under a Zeiss Axioimager 2 epifluorescence microscope equipped with a CCD camera and with the AxioVision software (Carl Zeiss MicroImaging, Jena, Germany), respectively.…”