Desert-Edge Contact Zone Between Goitered Gazelle Subspecies in Northeastern Iran

The vulnerable goitered gazelle (<i>Gazella subgutturosa</i>) comprises two evolutionarily distinct subspecies in Iran, separated by the central deserts as biogeographic barriers: <i>G. s. yarkandensis</i> (northeast) and <i>G. s. subgutturosa</i> (elsewhere). Using mitochondrial cytochrome <i>b </i>(307 sequences) and nuclear markers (CHD2, ZNF618), we resolved subspecies status in understudied northeastern Iran. Results confirmed <i>G. s. yarkandensis</i> predominance but revealed two pure <i>G. s. subgutturosa</i> haplotypes (H70, H78) through combined genetic analyses. H70 was previously associated with hybrids in central Iran, while H78 was novel. Phylogenetically, both clustered within the <i>G. s. subgutturosa</i> clade adjacent to hybrid haplotypes, with H78 one mutation from H70. Nuclear diagnostics confirmed subspecies identity, rejecting hybrid origins. Critically, H78 occurred naturally at Eshqabad No Hunting Area (northeastern Dasht-e Kavir edge), with H70 at Qayen Breeding Center (translocated). This identifies the northeastern edge of the Dasht-e Kavir as a contact zone where <i>G. s. subgutturosa</i> likely traverses the central deserts into northeastern Iran, overlapping with predominant <i>G. s. yarkandensis</i>. This contact may be facilitated by the latter's westward range expansion from Central Asia. Desert-edge habitats are thus vital conservation priorities, requiring genetic monitoring to maintain subspecies integrity and secure prey for the critically endangered Asiatic cheetah (&lt;50 individuals).