Aquaporins in Desert Rodent Physiology

Abstract

Desert rodents face a sizeable challenge in maintaining salt and water homeostasis due to their life in an arid environment. A number of their organ systems exhibit functional characteristics that limit water loss above that which occurs in non-desert species under similar conditions. These systems include renal, pulmonary, gastrointestinal, nasal, and skin epithelia. The desert rodent kidney preserves body water by producing a highly concentrated urine that reaches a maximum osmolality nearly three times that of the common laboratory rat. The precise mechanism by which urine is concentrated in any mammal is unknown. Insights into the process may be more apparent in species that produce highly concentrated urine. Aquaporin water channels play a fundamental role in water transport in several desert rodent organ systems. The role of aquaporins in facilitating highly effective water preservation in desert rodents is only beginning to be explored. The organ systems of desert rodents and their associated AQPs are described.

Plasticity in gene expression facilitates invasion of the desert environment in house mice

“…Aqp1 is expressed in the descending loop of Henle, and channels formed 395 from this protein are the main route through which water is reabsorbed in this region 396 (Chou et al, 1999). It is known to affect urine concentrating ability, response to 397 dehydration, and renal water transport in lab lines of house mice (Ma et al, 1998;Sohara et 398 al., 2005) and has been identified in a several studies related to desert adaptation in 399 rodents (reviewed in Pannabecker, 2015). In our analyses, expression of Aqp1 was 400 associated with variation in six of the nine measured phenotypes (Creatinine, p=0.020; 401 total protein, p=0.012; potassium, p=0.0094; weight loss, p=0.016; kidney weight, 402 p=0.0077; RWC, p=0.022).…”

Gene expression plasticity and desert adaptation in house mice*

“…1998; Sohara et al. 2005) and this protein family has been identified in a several studies related to desert adaptation in rodents (reviewed in Pannabecker 2015).…”

Immunohistochemical Study of Aquaporin 1 and 2 in the Hepatobiliary System of Qinghai Lizard ( Phrynocephalus vlangalii )

“…Distribution of AQP1 and AQP2 in the hepatobiliary system of Qinghai Lizard was similar to laboratory animals (Pannabecker, 2015), suggesting that they play constitutive role in maintaining water balance, water transmation and absorption. Living environment for Qinghai Lizard is extremely arid, environment pressure may be promoted the evolution of proteins related to water metabolism, improving animal to adapt to the environment.…”