Photoperiod and Reproduction in Flying Squirrels, Glaucomys Volans

1969 ◽  
Vol 50 (3) ◽  
pp. 542-549 ◽  
Author(s):  
I. Muul
1990 ◽  
Vol 68 (1) ◽  
pp. 134-139 ◽  
Author(s):  
Theresa M. Lee ◽  
Irving Zucker

Southern flying squirrels were housed in a simulated natural photoperiod for 40°N latitude and held at a constant temperature of 23 °C with food and water provided ad libitum. Body weight and reproductive condition were monitored weekly for 2 years. Males were in reproductive condition between January and mid-August and females were in estrus from late February to mid-April and again from mid-June until early August. Young were conceived during both estrous periods and several squirrels produced two litters in the same year. Minimum body weights were recorded in adults in mid-October each year. Pups born in the spring grew more rapidly than those from summer litters, and reached puberty at 2.5 months as compared with 6–8 months of age for the summer litters. Several seasonal rhythms appear to be controlled by photoperiod in this species.


2018 ◽  
Vol 96 (10) ◽  
pp. 1090-1096 ◽  
Author(s):  
Lanna M. Desantis ◽  
Jeff Bowman ◽  
Erin Faught ◽  
Rudy Boonstra ◽  
Mathilakath M. Vijayan ◽  
...  

Corticosteroid-binding globulin (CBG) helps to regulate tissue bioavailability of circulating glucocorticoids (GCs), and in most vertebrates, ≥80%–90% of GCs bind to this protein. New World flying squirrels have higher plasma total cortisol levels (the primary corticosteroid in sciurids) than most vertebrates. Recent research suggests that flying squirrels have either low amounts of CBG or CBG molecules that have a low binding affinity for cortisol, as this taxon appears to exhibit very low proportions of cortisol bound to CBG. To test whether CBG levels have been adjusted over evolutionary time, we assessed the levels of this protein in the plasma of northern (Glaucomys sabrinus (Shaw, 1801)) and southern (Glaucomys volans (Linnaeus, 1758)) flying squirrels using immunoblotting, and compared the relative levels among three phylogenetically related species of sciurids. We also compared the pattern of CBG levels with cortisol levels for the same individuals. Flying squirrels had higher cortisol levels than the other species, but similar levels of CBG to their closest relatives (tree squirrels). We conclude that CBG levels in flying squirrels have not been adjusted over evolutionary time, and thus, the uncoupling of CBG levels from cortisol concentrations may represent an evolutionary modification in the lineage leading to New World flying squirrels.


2019 ◽  
Vol 18 (3) ◽  
pp. 476
Author(s):  
Brett A. DeGregorio ◽  
Jinelle H. Sperry ◽  
Daniel G. Kovar ◽  
David A. Steen

2001 ◽  
Vol 82 (1) ◽  
pp. 51-64 ◽  
Author(s):  
J. F. Merritt ◽  
D. A. Zegers ◽  
L. R. Rose

2010 ◽  
Vol 91 (4) ◽  
pp. 897-904 ◽  
Author(s):  
Katherine K. Thorington ◽  
Jackie D. Metheny ◽  
Matina C. Kalcounis-Rueppell ◽  
Peter D. Weigl

2021 ◽  
Author(s):  
Jesse F Wolf ◽  
Jeff Bowman ◽  
Sonesinh Keobouasone ◽  
Rebecca S Taylor ◽  
Paul J Wilson

Northern (Glaucomys sabrinus) and southern (Glaucomys volans) flying squirrels are widespread species distributed across much of North America. Northern flying squirrels are common inhabitants of the boreal forest, also occurring in coniferous forest remnants farther south, whereas the southern flying squirrel range is centered in eastern temperate woodlands. These two flying squirrel species exhibit a hybrid zone across a latitudinal gradient in an area of recent secondary contact. Glaucomys hybrid offspring are viable and can successfully backcross with either parental species, however, the fitness implications of such events are currently unknown. Some populations of G. sabrinus are endangered, and thus, interspecific hybridization is a key conservation concern in flying squirrels. We sequenced and assembled a de novo long-read genome from a G. volans individual sampled in southern Ontario, Canada, while four short-read genomes (2 G. sabrinus and 2 G. volans, all from Ontario) were re-sequenced on Illumina platforms. The final genome assembly consisted of approximately 2.40Gb with a scaffold N50 of 455.26Kb. Benchmarking Universal Single-Copy Orthologs reconstructed 3,742 (91.2%) complete mammalian genes, and genome annotation using RNA-seq identified the locations of 19,124 protein-coding genes. The four short-read individuals were aligned to our reference genome to investigate the demographic history of the two species. A Principal Component Analysis clearly separated re-sequenced individuals, while inferring population size history using the Pairwise Sequentially Markovian Coalescent model noted an approximate species split one million years ago, and a single, possibly recently introgressed individual.


Sign in / Sign up

Export Citation Format

Share Document