Browsing by Author "Luziga,C"

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Penile and prostate morphology of the African giant pouched rat
(Tanzania Veterinary Journal, 2023) Ngalameno,M.K; Luziga,C
The African giant pouched rat, Cricetomys gambianus is a solitary rodent, distributed in savannah of Southern and Eastern Africa with socio-economical importance in landmines and tuberculosis detection. Despite of their importance, there are limited anatomical studies focusing on the reproductive organs of C. gambianus. This study was set to evaluate gross and histological features of the penis and prostate glands of C. gambianus. Ten sexually matured C. gambianus (1.0 + 0.1kg) were trapped from the wild and sacrificed using overdose of absolute halothane inhalation. After gross anatomical studies, penile and prostate samples were collected for histological studies. Gross evaluation revealed that, the penis of C. gambianus was caudo-ventrally oriented. Average length of measured anatomical parts were: anogenital distance (6.31 + 0.89 cm); total penis length (6.66 + 0.3 cm), root (2.0 + 0.1cm),shaft (3.77 + 0.3 cm), and glans penis (0.89 + 0.2 cm). The average length of the os penis was 1.8 + 0.1 cm and its tip was visible through the urethral opening at the glans penis, while its base was attached to the shaft just after the collum penis groove. Microscopically, different parts of the penis showed variable histological composition and organization. Furthemore, the prostate gland consisted of dorsal, lateral and ventral lobes with small, moderate, and few short intraglandular epithelial foldings with acini lined by simple cuboidal to columnar epithelium.
The pattern of reproduction in the African giant pouchedrat, Cricetomys gambianus, from Tanzania: unravelling the environmental triggers for breeding
(Canadian Science Publishing, 2024) Ngalamenoa,M.K; Luziga,C; Hart,D.W; Bennettd,N.C
Our research represents the first extensive study of the breeding behaviour and related environmental triggers of reproduction in the African giant pouch rat (Cricetomys gambianus Waterhouse, 1840) in and around the equator throughout a whole year. We measured the gross morphology and detailed histology of both female and male rats, along with plasma steroid hormone levels. Contrary to other tropical-dwelling small mammals, the African giant pouch rat is a seasonal breeder; however, rainfall is not to be the primary cue of reproduction. Our study suggests that ambient temperature and photoperiod are the primary environmental cues of reproduction, with breeding occurring during the cooler months of the year, namely in the dry season. During the wet and hot season, which succeeds the dry season, there is an increase in the availability of quality food, which results in nursing mothers and weaned pups achieving a positive energy balance and increased body condition. This, in turn, increases pregnancy success and offspring survival. Climate change, particularly global warming, could harm the reproduction of African giant pouched rats as rising temperatures in and around the equator, including Tanzania, may impact their circannual reproductive cycle
Uncovering the identity of the living laboratory: a combined approach of COI gene sequencing and phylogenetic analysis of the African giant pouched rats
(Tanzania Veterinary Journal, 2022) Ngalameno,M. K; Luziga,C
The African giant pouched rats belongs to the genus Cricetomys and they are exploited to aid the detection of landmines in landmine affected areas in different countries, and for diagnosing pulmonary tuberculosis in health laboratories. These rats are usually captured within Morogoro Tanzania and trained at Sokoine University of Agriculture before deploymemt for actual action. However there is a dearth of information on the taxonomy and phylogeny of Cricetomys species occurring in Tanzania. This study used phenotypic appearance, polymerase chain reaction (PCR) amplification and sequensing of cytochrome oxidase subunit I (COI) gene from one hundred and twenty African giant pouched rats trapped from the wild to characterize and identify the phenotypes and identity of the rats. Two groups were identified based on colour of the pelage; the grey group 68% (n=82) and brown group 32% (n=38). The phylogeny and molecular evolutionary analyses revealed the maximum nucleotides homology of 100% and minimum of 97.3% with Cricetomys gambianus despite the differences in their pelage colour. This study identified the esistence of Cricetomys gambianus species as a dominant species in Morogoro Municipality.