Biology subjects

Pennington, P. M.

Publications and source records attributed to Pennington, P. M..

3 recordsLinked to original sources

bioRxiv2026

Transvaginal ovum retrieval in scimitar horned oryx (Oryx dammah) and roan antelope (Hippotragus equinus)

Development and use of assisted reproductive technologies (ARTs) in non-domestic species provides novel tools for species conservation. As a first step towards in vitro embryo production, we developed an OPU technique for two antelope species, scimitar horned oryx (Oryx dammah) and roan antelope (Hippotragus equinus) utilizing a custom-made needle guide and existing OPU equipment utilized by livestock and human practitioners. Females were anesthetized and placed in sternal recumbency for transvaginal OPUs. Prior to OPUs (36 - 45 hours), SHO and roan were either hormonally stimulated with follicle stimulating hormone (FSH, 140 or 250IU) as a single injection or not. A total of 32 and 26 OPUs were completed in SHO (n=10) and roan (n=7), respectively, representing one to four OPUs per animal at monthly intervals. A total of 141 oocytes were recovered from 215 follicles in SHO and 31 oocytes from 58 follicles in roan. FSH dose (250IU) increased (P<0.05) the number of follicles aspirated and the number of oocytes recovered in SHO. No effects of FSH were observed in roan (P>0.05). Good quality oocytes were recovered from all females and procedures were conducted in four consecutive months with no evidence of scar tissue buildup or reduced capacity to recover quality oocytes. These ARTs can be used to develop in vitro embryo production tools for population management and the preservation of female genetics; bolstering genetic diversity and guarding against extinction.

physiology↗

bioRxiv2025

Advancing the design of the kissing bug kill trap for surveillance of triatomines

Standardized surveillance and control of kissing bugs (Hemiptera: Reduviidae: Triatominae), the insect vectors of the Chagas disease parasite Trypanosoma cruzi, which causes Chagas disease, remains difficult. The Kissing Bug Kill Trap consists of solar powered LED lights mounted over a column of black funnels. It operates autonomously to capture, kill and preserve adult triatomines. We conducted experiments from 2022-2024 testing potential ways to improve trap performance, ease of deployment, and minimize cost. Thirteen prototypes evaluated in Texas, Guatemala, and Mexico captured 1,531 triatomines. In 2022-2023 we selected a six-funnel trap suspended from a single support pole with an angle bracket, and with four LED lights and a solar panel mounted above the rain-guard, as a reference trap. In 2023, traps with smaller funnels, blue funnels, and blue lights were inferior to the reference trap based on high by-catch of other arthropods and/or fewer triatomines caught per day. In 2024, traps with more or fewer than six funnels or with LED lights mounted on or below the rain guard did not outperform the reference trap. The experiments added five new triatomine species to the four already known to be caught by the Kissing Bug Kill Trap and revealed differences and similarities in phenology of dispersal flights of Triatoma gerstaeckeri over a three-year period in Texas. The reference trap was selected as the pre-commercial prototype, based on its suitability for triatomine surveillance and potential for reducing the risk of T. cruzi infection by intercepting dispersing adult triatomines before they reach human habitats.

ecology↗

bioRxiv2024

Wild lytic bacteriophages: a potential enhancer of disinfectants biofilm inhibition in bio-industrial settings for fruit fly production.

The pathogenic nature of Morganella morganii to fruit flies has been described earlier; its biofilm prevents the larvae of mass reared fruit flies from proceeding to their next life stage by trapping them in their polymeric matrix. For the Mediterranean (Ceratitis capitata) fruit fly ("medfly") mass rearing plants, this can be problem, due to losses generated in the production process. The presence of this bacteria is prevented by using different disinfectants, by themselves, or combined, which can act as selective pressure for the biofilm to resist the disinfectants. In this paper, we propose a method to isolate lytic bacteriophages and use them as quorum quenchers, to prevent microbial consortium from forming biofilms. When tried as viral cocktails, a very significant reduction of biofilm was found. However, when used with one of the two tried industrial disinfectants, the viral effect wasnt as significant. When interpreted alongside the first experiments, this result opens the door to use bacteriophages to reduce the minimum inhibitory concentration necessary of the disinfectant. A reduction of said concentration would translate into less selective pressure for a resistance against it, and a reduction in costs for the mass rearing process at the time of implementation of the system.

bioengineering↗