{'fraction_non_alphanumeric': 0.03343465045592705, 'fraction_numerical': 0.009878419452887538, 'mean_word_length': 5.51980198019802, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Chromosome Characterization of an Endemic South American Rodent, Calomys hummelincki (Husson, 1960) (Sigmodontinae, Phyllotini)

Abstract The main objective of this research was the chromosomal characterization of the sigmodontine rodent Calomys hummelincki (Husson, 1960), which belongs to the Tribe Phyllotini. The distribution of C. hummelincki is restricted to a region of northern South America, comprising Venezuela, Aruba, Curaçao and probably the Colombian llanos and Guajira Peninsula. For this study, we collected specimens in Venezuela, Aruba and Curaçao. The cytogenetic analysis showed that all six populations studied displayed the same diploid number (2n=60) and fundamental number (FN=64). Constitutive heterochromatin was observed in a pericentromeric position in almost all chromosomes. NOR regions were observed in four pairs of acrocentric chromosomes. Chromomycin/DAPI fluorescent staining revealed the presence of particular euchromatin fluorescent blocks in some chromosomes. G-banding allowed us to identify almost all pair positions of the C. hummelincki chromosome complement. G-banding also permitted a comparison of the C. hummelincki pattern with those published for C. callidus, C. venustus and C. laucha. The results indicate that C. hummelincki is not directly derived from C. laucha.