A Genetic Journey to Ancient Roots

Introduction

As a breeder dedicated to preserving the rare Chongqing Dog, a molosser-type breed with a small global population, I rely on genetic testing to ensure health and maintain heritage. Our dog, Moli, underwent Embark’s comprehensive DNA test, revealing her as 100% purebred with clear health results, distinctive traits, and a maternal lineage tracing back to the dawn of dog domestication. This article explores Moli’s results, from her clean bill of health to her iconic coat and ancient roots, drawing on the test and scientific insights from a 2009 study on dog origins, to inform enthusiasts and guide responsible breeding.

The Embark Test: A Tool for Responsible Breeding

Embark’s canine DNA test analyzes multiple genetic markers to provide insights into ancestry, health (over 270 conditions), and traits like coat color and body structure. For a rare breed like the Chinese Chongqing Dog, with limited genetic diversity, this test is vital to identify potential health risks and confirm purity, reducing inbreeding risks. Moli’s test was straightforward: we used cheek swab from the kit, and shipped it to Embark’s lab in San Diego via Poczta Polska, a cost-effective choice over pricier FedEx. Results arrived online within weeks, offering a detailed dashboard to guide breeding decisions.

Moli’s Health: A Clean Slate for a Robust Breed

The Chinese Chongqing Dog, with proposed classification in FCI Group 2 alongside mastiffs, can be prone to health issues common to molossers due to their sturdy build. Moli’s results are exceptional, showing her clear for all 273 conditions tested, ensuring she’s unlikely to develop or pass on these issues. Key clearances include:

Dilated Cardiomyopathy: A heart condition where the muscle weakens, risking failure, seen in breeds like Dobermans. Moli’s clear status supports her vitality.
Degenerative Myelopathy: A spinal disease causing progressive weakness, common in large breeds. Her clearance ensures mobility for her guarding role.
Intervertebral Disc Disease: Spinal disc issues leading to pain and mobility loss, seen in robust breeds. Moli’s clear result promotes her active lifestyle.
Mucopolysaccharidosis: Metabolic disorders causing joint and organ issues, affecting working dogs. Moli’s clearance avoids these risks.
Progressive Retinal Atrophy: An eye condition leading to blindness, prevalent in mastiffs. Her clear vision is key for hunting heritage.
Von Willebrand’s Disease: A bleeding disorder causing excessive bleeding, seen in some molossers. Moli’s clear status reduces surgical risks.

These results make Moli a strong breeding candidate, minimizing hereditary concerns in a breed with a small population, unlike some ancient Asian breeds facing issues like familial Shar Pei fever (recurrent inflammation).

Moli’s Traits: Practical Elegance for a Historic Role

Moli boasts a captivating mahogany red coat with a distinctive black mask, a classic phenotype for her breed that's deeply rooted in her genetic makeup. At the core of her color genetics are the key loci: MC1R (EE), allowing full expression of both eumelanin (black pigment) and pheomelanin (red pigment); CBD103 or K locus (k^yk^y), which permits the A locus to dictate her pattern; and ASIP or A locus (A^ya^t), where the dominant A^y allele for sable promotes a predominantly red body while the carried a^t (tan points) may influence shading, resulting in her red appearance with black shading and eumelanin concentrated on the muzzle for that signature black mask. Her non-dilute status is confirmed by MLPH or D locus (DD) and TYRP1 or B locus (BB), ensuring rich, undiluted black and red pigments without any brown, blues or other faded tones. The intensity of her deep mahogany red stems from polygenic modifiers at the pheomelanin intensity loci—chr18 (red/red), KITLG (red/red), and MFSD12 (red/red) contribute to dense pigment concentration, outweighing the cream/cream variants at chr2 and chr21 for an overall vibrant hue rather than a paler cream. Additional loci like MITF or S locus (SS) for solid coloring with no white spotting, and wildtypes such as HPS3 (NN), RALY (NN), PMEL (mm), USH2A (rr), H locus (hh), and panda (NN) keep her coat uniform and free from merle, harlequin, or other patterns. This genetic cocktail not only explains her intense red body but also the contrasting black muzzle, where eumelanin dominates the facial area as permitted by her sable genetics, making her a perfect embodiment of the Chongqing Dog's ancient, bold aesthetic.

The test predicted an adult weight of around 44 pounds (approximately 20 kg), closely matching her actual weight of 19.5 kg, confirming her lean, agile build over bulk. This supports her endurance for tasks like trailing scents. Her coat is short to mid-length, straight, and low-shedding, requiring minimal grooming—ideal for warm climates and complementing the breed’s hairless ears and tail. Her medium-length muzzle avoids breathing issues, and her standard tail and lack of extra dewclaws ensure a fluid gait. Moli’s moderate appetite prevents obesity risks, and her dark, alert eyes align with her vigilant nature, with no blue-eye predisposition. These traits embody a resilient, low-maintenance dog, distinct from heavily modified breeds, tailored for the breed’s multi-purpose heritage.

Ancient Origins: Moli’s Lineage and Dog Domestication

Moli's maternal genetic lineage offers a fascinating glimpse into her ancient heritage. Her mitochondrial DNA belongs to haplogroup B2, a rare subclade within the broader B haplogroup. While haplogroup B accounts for 15-20% of global dog lineages, B2 is much rarer, appearing in less than 5%, mostly in East and Southeast Asia. This lineage, which likely arose thousands of years ago, connects her to early domesticated dogs from the upper Yangtze River basin, a region that includes both Sichuan and Chongqing, and highlights the historical significance of the Chongqing Dog. Her specific haplotype, B5/23, points to a unique and distinct population of ancient dogs, a living connection to the canine companions of ancient Chinese culture. However, we cannot analyze her paternal lineage, as Moli is female and lacks the Y chromosome needed to trace the male line through genetic markers.

Summary

Moli’s Embark results—clear health, practical traits, and rare B2 lineage—paint a picture of a robust, versatile Chinese Chongqing Dog, true to her roots as a guardian and hunter. For breeders, these insights guide ethical pairings to sustain health and heritage in this rare breed. For enthusiasts, Moli’s story celebrates the enduring bond between humans and dogs, forged millennia ago along the Yangtze.

Sources

The maps included as images in this article are taken from the cited scientific publication by Pang et al. (2009).

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