The red-tailed phascogale is a ‘Near Threatened’ dasyurid marsupial. Males are semelparous and die off shortly after the breeding season in the wild due to a stress-related syndrome, which has many physiological and immunological repercussions. In captivity, males survive for more than 2 years but become infertile after their first breeding season. Meanwhile, females can breed for many years. This suggests that captive males develop similar endocrine changes as their wild counterparts and undergo accelerated aging. However, this remains to be confirmed. The health status and immune function of this species in captivity have also yet to be characterized. Through an integrative approach combining post-mortem examinations, blood biochemical and hematological analyses, we investigated the physiological and health status of captive phascogales before, during, and after the breeding season. Adult males showed only mild lesions compatible with an endocrine disorder. Both sexes globally maintained a good body condition throughout their lives, most likely due to a high quality diet. However, biochemistry changes potentially compatible with an early onset of renal or hepatic insufficiency were detected in older individuals. Masses and possible hypocalcemia were observed anecdotally in old females. With this increased knowledge of the physiological status of captive phascogales, interpretation of their immune profile at different age stages was then attempted. During the breeding season, males developed a stress leukogram characterized by a marked lymphopenia, further aggravated by a severe leukopenia after the breeding season. To determine whether these changes were limited to the peripheral blood or had more profound implications, histopathology of the spleen was performed opportunistically. Adult males showed white pulp atrophy, at various degrees. The atrophy was mainly lymphoid and more severe in 1.5-year-old males than in 3.5-year-old females. These results suggest that captive males undergo accelerated immunosenescence. Functional studies are now needed to characterize the underlying mechanisms leading to immunosenescence in marsupials. Semelparous dasyurids present great potential for studying the effects of sex and stress on immunity in marsupials. Characterization of these immune-endocrine interactions may help refine veterinary treatment plans, husbandry protocols and conservation programs to maintain the health of captive and wild populations.

中文翻译：

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圈养的有节状有袋动物，红尾（Phascogale calura）的免疫发光

红尾目鱼是“濒临灭绝”的达苏里德有袋动物。雄性互生，在野生的繁殖季节后不久因压力相关综合症而死亡，该综合症具有许多生理和免疫学影响。在圈养中，雄性存活超过2年，但在第一个繁殖季节后变得不育。同时，雌性可以繁殖很多年。这表明，圈养的雄性与野生型雄性相比具有相似的内分泌变化，并会加速衰老。但是，这仍有待确认。该物种在圈养中的健康状况和免疫功能也尚未确定。通过将验尸，血液生化和血液学分析相结合的综合方法，我们调查了被捕食的捕蝇草的生理和健康状况，在繁殖季节期间和之后。成年男性仅表现出与内分泌失调相容的轻度病变。全球两性一生都保持良好的身体状况，这很可能归因于高质量的饮食。但是，在老年个体中发现了与肾脏或肝功能不全的早期发作潜在相容的生化变化。在老年女性中轶事地观察到肿块和可能的低血钙症。随着对圈养捕虫sco的生理状态的了解增加，然后尝试解释其在不同年龄阶段的免疫特性。在繁殖季节，雄性出现了应激性白血球，特征是明显的淋巴细胞减少症，繁殖季节后严重的白血球减少症进一步加剧了这种情况。为了确定这些变化是局限在外周血还是具有更深远的意义，随机进行了脾脏的组织病理学检查。成年男性在不同程度上表现出白髓萎缩。在1.5岁的男性中，萎缩主要是淋巴样，并且比3.5岁的女性更为严重。这些结果表明，圈养的雄性经历加速的免疫衰老。现在需要功能研究来表征导致有袋动物免疫衰老的潜在机制。粗大的假鳞蝇为研究有性和有压力的有袋动物的免疫力提供了巨大的潜力。这些免疫-内分泌相互作用的特征可能有助于完善兽医治疗计划，饲养协议和保护计划，以保持圈养和野生种群的健康。