Anolis uniformis Cope, 1885

Castiglia, Riccardo, Flores-Villela, Oscar Alberto, Bezerra, Alexandra M. R., Gornung, Ekaterina, Annesi, Flavia, Munoz-Alonso, Luis Antonio & Solano, Emanuela, 2020, Detection of cryptic diversity in lizards (Squamata) from two Biosphere Reserves in Mesoamerica, Comparative Cytogenetics 14 (4), pp. 613-638 : 613

Anolis uniformis Cope, 1885

Distribution.

Occurs from southern Tamaulipas to north-central Honduras on the Atlantic coast.

Samples.

RCMX201 (male), RCMX203 (male), RCMX205 (male*), RCMX206 (female*), RCMX209 (female), RCMX210 (male*), RCMX215 (male*) and RCMX226 (female*) from Estación Chajul, Selva Lacandona, Montes Azules, Chiapas, Mexico.

DNA taxonomy.

The species was formerly included in the A. humilis group, but it is now included in the Draconura clade ( Poe et al. 2017). Over the 780-bp of the MT-ND2 fragment, the GenBank BLAST reports a 99% identity with A. uniformis from Belize (KJ954096 and KJ954099).

Chromosomes.

We report here the first description of the karyotype of this species (Fig. 8C ). The species is characterized by X1X1X2X2/X1X2Y sex chromosome system. In fact, male individuals have a chromosome number 2n = 29 (14M + 15m) and females show 2n = 30 (14M + 16m). The macrochromosomes can be morphologically divided in two pairs of large metacentrics, three pairs of medium sized metacentrics, one pair of small metacentric and one pair of small acrocentric chromosomes. The X1 was identified as an acrocentric chromosome and X2 as a microchromosome. The Y chromosome is an acrocentric one similar in size to X1.

Among the species of the genus Anolis with a known karyotype, this species is phylogenetically close to A. aquaticus Taylor, 1956 and A. biporcatus . Furthermore, A. biporcatus has also a similar composition of the sex chromosomes system, even if the morphology of sex chromosomes is different. In fact, the so-called 2n = 30 karyotype is one of the most common karyotypes in Anolis . However, three variants of this karyotype, based on the number and shape of macro- and microchromosomes, have been described. Among them, two types of 2n = 29-30 are present, type-A and type-B ( Castiglia et al. 2010).

The type-A, typical of A. biporcatus , presents a multiple sex chromosomes system where X1 is an acrocentric chromosome, X2 is a microchromosome, and Y is metacentric similar in size to X1.

In our case, the Y is a small acrocentric chromosome, which might have been derived from a pericentric inversion in the submetacentric Y chromosome of the 2n = 29-30 type-A karyotype.Thus, although it is believed that the onset of multiple sex chromosomes in Anolis occurs independently ( Castiglia et al. 2013b; Gamble et al. 2014), present data suggest that this condition may represent a trait derived from the common ancestor of the two species.

Figures

Figure 8. Karyotypes of A Anolis capito (2 n = 40, RCMX 218 female) B Anolis lemurinus (2 n = 40, RCMX 214 male) and C Anolis uniformis (2 n = 50, RCMX 210 male) with YX 1 X 2 sex chromosomes; in the box the X 1 X 1 X 2 X 2 (RCMX 206 female) sex chromosomes.