Evidencias moleculares de hibridación entre
Serinus canaria domestica (L., 1758) y Spinus
barbatus (Molina, 1782) (Aves: Fringillidae)
Authors: Díaz Leila , Correa Víctor Alejandro , Nuñez José J. 
Published: December 2019

Resumen
En este estudio se muestran evidencias moleculares de éxito en la hibridación entre Serinus canaria domestica (linnaeus, 1758) y Spinus barbatus (molina, 1782). Como parte de una
secuencia de retrocruzamiento, se logró reproducir híbridos F2 a partir de hembras híbridas
fértiles viables F1 x S. c. domestica. La F1 fue la descendencia entre P0
= Serinus c. domestica x Spinus barbatus. Las secuencias de nucleótidos de dos segmentos de ADN, citocromo b mitocondrial (Cyt b) y el receptor de tirosina quinasa muscular (MuSK) del ADN nuclear se obtuvieron
de tres especímenes híbridos F2. Tanto las secuencias de Cyt b como de MuSK señalaron fuerte
soporte filogenético a la condición genética híbrida de los tres embriones F2. De esta manera la
evidencia molecular refleja el éxito en el cruce interespecífico entre S. barbatus con S. c. domestica y que es posible obtener híbridos fértiles viables F1 (en este caso hembras) y F2 entre estos
dos linajes en poblaciones naturales.
Abstract
In this study we show molecular evidences of success in hybridization between Serinus
canaria domestica and Spinus barbatus. As part of a sequence of backcrossing we have achieved to
reproduce F2 hybrids of fertile hybrid females F1 with parental S. c. domestica. F1 was the offspring between, P0
= S. c. domestica x S. barbatus. In this study the space where the observations
and the breeding success are carried out between these species, they are described: is a room
with the following measures; 4,45 m (lenghty) x 1,60 m (width) x 2,30 m (high), located in an
urban building; specifically, glassed-balcony at a height of 10,60 m above ground level, facing some
ornamental and exuberant canopy trees of Platanus orientalis (L., 1753) and with direct entrance
of natural sunlight, in urban city of Santiago, Chile, where his perceptual world develops. We
took care to keep the biotic and abiotic factors under control; specifically, incoming natural light,
ambient vegetation and temperature. On the other hand, we fed the individuals appropriately
and provided them with plenty of clean water to drink and get clean, where there were no predators. In sum, the individuals were kept in a healthy environment. The backcrossing between the
male S. c. domestica (generation 0) bred with two viable hybrid F1 offspring females, it gave as resulted in a total of three independent generations of F2 hybrids (n = 12). All the individuals came
out healthy, and none of them died, despite being inbred lineages. Three embryos representative
of the F2 hybrids were sacrificed and deposited in 99% alcohol. Nucleotide sequences of two
DNA segments, mitochondrial cytochrome b (Cyt b) and muscle-specific receptor tyrosine
kinase (MuSK) gene of the nuclear DNA were obtained from three F2 hybrid specimens. The
model of molecular evolution with the greatest adjustment to the data obtained by jModeltest
was GTR + I + G (I = 0,1450, G = 0,0930), according to the phylogenetic analysis of mitochondrial DNA (Fig. 1a), the female progenitor P0
is S.c.domestica. This conclusion is based on the evi-
dence that mitochondrial DNA in birds, as well as in most animal groups, is exclusively inherited
through the maternal ways. The same analysis carried out with the nuclear MuSK gene shows
that the parental male P0
of the embryos analyzed is very much related to S. barbatus (Fig. 1b).
The Cyt b and MuSK region show strongly support to hybrids genetic condition of the three F2
embryos. Intergeneric hybrids are usually sterile, but it is worth noting that genera of Fringillidae
are very closely related (the Family as a whole is only 12 million years old, and most genera in
the terminal canary-siskin group are <5 million years old). This is simply a case of poor classification with oversplitting or maybe the nature of these lineages are fractals, since in most of the
Passeriformes, family-level taxa are more than 20 million years old, and in other groups of Aves
families and genera are even older. Then hybridization takes place more easily in captivity. Many
authors considered that hybridization in birds is not important because hybrids are formed in
proportion 1/50,000 specimens. Despite this, many bird hybrids have been created in captivity.
In addition, hybrids produced ex situ under controlled conditions would play an important
role for reproductive success and subsequent interspecific viability. The main conclusions derived from this study are as follows:
1) The present report strongly indicates that hybridizations have occurred among S. c.
canary x S. barbatus. 2) In this way the molecular evidence reflects and justifies the success
in interspecific reproduction between S. barbatus with S. c. domestica and that it is possible to
obtain viable fertile hybrids F1 (in this case females) and F2 between these two lineages, 3) And
consequently the close genetic affinity between these two genera and the formation of hybrids
in natural populations should not discard.