MSc Student – Cell & Systems Biology
Thesis title: TBD
B.S. Hon. (University of Toronto Scarborough, Toronto, ON, Canada, 2017)
E-mail: saad.muhammad@mail.utoronto.ca
Selected Publications
5126420
D55ZIPIZ
items
1
0
date
asc
year
1
1
221
https://www.welchbiology.com/wp-content/plugins/zotpress/
%7B%22status%22%3A%22success%22%2C%22updateneeded%22%3Afalse%2C%22instance%22%3A%22zotpress-0346106a71e9552c3aa10e44b7b3ff30%22%2C%22meta%22%3A%7B%22request_last%22%3A0%2C%22request_next%22%3A0%2C%22used_cache%22%3Atrue%7D%2C%22data%22%3A%5B%7B%22key%22%3A%228ICF39TB%22%2C%22library%22%3A%7B%22id%22%3A5126420%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Ali%20et%20al.%22%2C%22parsedDate%22%3A%222020-10-27%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%201.35%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3E%3Cb%3EAli%2C%20R.%20S.%2C%20Dick%2C%20M.%20F.%2C%20Muhammad%2C%20S.%2C%20Sarver%2C%20D.%2C%20Hou%2C%20L.%2C%20G.%20William%20Wong%20and%20Welch%2C%20K.%3C%5C%2Fb%3E%20%282020%29.%20Glucose%20transporter%20expression%20and%20regulation%20following%20a%20fast%20in%20the%20ruby-throated%20hummingbird%2C%20%3Ci%3EArchilochus%20colubris%3C%5C%2Fi%3E.%20%3Ci%3EJournal%20of%20Experimental%20Biology%3C%5C%2Fi%3E%20%3Cb%3E223%3C%5C%2Fb%3E%2C%20jeb229989.%20%3Ca%20title%3D%27Download%27%20class%3D%27zp-DownloadURL%27%20href%3D%27https%3A%5C%2F%5C%2Fwww.welchbiology.com%5C%2Fwp-content%5C%2Fplugins%5C%2Fzotpress%5C%2Flib%5C%2Frequest%5C%2Frequest.dl.php%3Fapi_user_id%3D5126420%26amp%3Bdlkey%3DG9SRSDXN%26amp%3Bcontent_type%3Dapplication%5C%2Fpdf%27%3EDownload%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Glucose%20transporter%20expression%20and%20regulation%20following%20a%20fast%20in%20the%20ruby-throated%20hummingbird%2C%20%3Ci%3EArchilochus%20colubris%3C%5C%2Fi%3E%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Raafay%20Syed%22%2C%22lastName%22%3A%22Ali%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Morag%20F.%22%2C%22lastName%22%3A%22Dick%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Saad%22%2C%22lastName%22%3A%22Muhammad%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Dylan%22%2C%22lastName%22%3A%22Sarver%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Lily%22%2C%22lastName%22%3A%22Hou%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22name%22%3A%22G.%20William%20Wong%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Kenneth%22%2C%22lastName%22%3A%22Welch%22%7D%5D%2C%22abstractNote%22%3A%22%3Cp%3EHummingbirds%20subsist%20almost%20exclusively%20on%20nectar%20sugar%20and%20face%20extreme%20challenges%20blood%20sugar%20regulation.%20Transmembrane%20sugar%20transport%20is%20mediated%20by%20facilitative%20glucose%20transporters%20%28GLUTs%29%20and%20the%20capacity%20for%20sugar%20transport%20is%20dependent%20on%20both%20the%20activity%20of%20GLUTs%20and%20their%20localisation%20to%20the%20plasma%20membrane%20%28PM%29.%20In%20this%20study%2C%20we%20determined%20the%20relative%20protein%20abundance%20in%20whole-tissue%20%28WT%29%20homogenates%20and%20PM%20fractions%20via%20immunoblot%20using%20custom%20antibodies%20for%20GLUT1%2C%20GLUT2%2C%20GLUT3%2C%20and%20GLUT5%20in%20flight%20muscle%2C%20heart%2C%20and%2C%20liver%20of%20ruby-throated%20hummingbirds%20%28Archilochus%20colubris%29.%20GLUTs%20examined%20were%20detected%20in%20nearly%20all%20tissues%20tested.%20Hepatic%20GLUT1%20was%20minimally%20present%20in%20WT%20homogenates%20and%20absent%20in%20PM%20fractions.%20GLUT5%20was%20expressed%20in%20hummingbird%20flight%20muscles%20at%20levels%20comparable%20to%20that%20of%20their%20liver%2C%20consistent%20with%20the%20hypothesised%20uniquely%20high%20fructose-uptake%20and%20oxidation%20capacity%20of%20this%20tissue.%20To%20assess%20GLUT%20regulation%2C%20we%20fed%20ruby-throated%20hummingbirds%201M%20sucrose%20ad%20libitum%20for%2024%20hours%20followed%20by%20either%201%20hour%20of%20fasting%20or%20continued%20ad%20libitum%20feeding%20until%20sampling.%20We%20measured%20relative%20GLUT%20abundance%20and%20concentrations%20of%20circulating%20sugars.%20Blood%20fructose%20concentration%20in%20fasted%20hummingbirds%20declined%20from%20~5mM%20to%20~0.18mM%2C%20while%20fructose-transporting%20PM%20GLUT2%20and%20PM%20GLUT5%20did%20not%20change%20in%20abundance.%20Blood%20glucose%20concentrations%20remained%20elevated%20in%20both%20fed%20and%20fasted%20hummingbirds%2C%20at%20~30mM%2C%20while%20glucose-transporting%20PM%20GLUT1%20and%20PM%20GLUT3%20in%20the%20flight%20muscle%20and%20liver%2C%20respectively%2C%20declined%20in%20fasted%20birds.%20Our%20results%20suggest%20that%20glucose%20uptake%20capacity%20is%20dynamically%20reduced%20in%20response%20to%20fasting%2C%20allowing%20for%20maintenance%20of%20elevated%20blood%20glucose%20levels%2C%20while%20fructose%20uptake%20capacity%20remains%20constitutively%20elevated%20promoting%20depletion%20of%20blood%20total%20fructose%20within%20the%20first%20hour%20of%20a%20fast.%3C%5C%2Fp%3E%22%2C%22date%22%3A%222020-10-27%22%2C%22language%22%3A%22en%22%2C%22DOI%22%3A%2210.1242%5C%2Fjeb.229989%22%2C%22ISSN%22%3A%22%22%2C%22url%22%3A%22https%3A%5C%2F%5C%2Fjeb.biologists.org%5C%2Fcontent%5C%2Fearly%5C%2F2020%5C%2F09%5C%2F04%5C%2Fjeb.229989%22%2C%22collections%22%3A%5B%22PUVBHFJ6%22%2C%227EZD2CLL%22%2C%225UIRG3NX%22%2C%22D55ZIPIZ%22%5D%2C%22dateModified%22%3A%222021-01-29T16%3A21%3A23Z%22%7D%7D%2C%7B%22key%22%3A%22JDEAVVPE%22%2C%22library%22%3A%7B%22id%22%3A5126420%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Gershman%20et%20al.%22%2C%22parsedDate%22%3A%222023-05-08%22%2C%22numChildren%22%3A1%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%201.35%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3E%3Cb%3EGershman%2C%20A.%2C%20Hauck%2C%20Q.%2C%20Dick%2C%20M.%2C%20Jamison%2C%20J.%20M.%2C%20Tassia%2C%20M.%2C%20Agirrezabala%2C%20X.%2C%20Muhammad%2C%20S.%2C%20Ali%2C%20R.%2C%20Workman%2C%20R.%20E.%2C%20Valle%2C%20M.%2C%20et%20al.%3C%5C%2Fb%3E%20%282023%29.%20Genomic%20insights%20into%20metabolic%20flux%20in%20hummingbirds.%20%3Ci%3EGenome%20Res.%3C%5C%2Fi%3E%20gr.276779.122.%20%3Ca%20title%3D%27Download%27%20class%3D%27zp-DownloadURL%27%20href%3D%27https%3A%5C%2F%5C%2Fwww.welchbiology.com%5C%2Fwp-content%5C%2Fplugins%5C%2Fzotpress%5C%2Flib%5C%2Frequest%5C%2Frequest.dl.php%3Fapi_user_id%3D5126420%26amp%3Bdlkey%3DH5QU3TVI%26amp%3Bcontent_type%3Dapplication%5C%2Fpdf%27%3EDownload%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Genomic%20insights%20into%20metabolic%20flux%20in%20hummingbirds%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ariel%22%2C%22lastName%22%3A%22Gershman%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Quinn%22%2C%22lastName%22%3A%22Hauck%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Morag%22%2C%22lastName%22%3A%22Dick%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jerrica%20M%22%2C%22lastName%22%3A%22Jamison%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Michael%22%2C%22lastName%22%3A%22Tassia%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Xabier%22%2C%22lastName%22%3A%22Agirrezabala%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Saad%22%2C%22lastName%22%3A%22Muhammad%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Raafay%22%2C%22lastName%22%3A%22Ali%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Rachael%20E.%22%2C%22lastName%22%3A%22Workman%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Mikel%22%2C%22lastName%22%3A%22Valle%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22G%20William%22%2C%22lastName%22%3A%22Wong%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Kenneth%20C%22%2C%22lastName%22%3A%22Welch%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Winston%22%2C%22lastName%22%3A%22Timp%22%7D%5D%2C%22abstractNote%22%3A%22Hummingbirds%20are%20very%20well%20adapted%20to%20sustain%20efficient%20and%20rapid%20metabolic%20shifts.%20They%20oxidize%20ingested%20nectar%20to%20directly%20fuel%20flight%20when%20foraging%20but%20have%20to%20switch%20to%20oxidizing%20stored%20lipids%20derived%20from%20ingested%20sugars%20during%20the%20night%20or%20long-distance%20migratory%20flights.%20Understanding%20how%20this%20organism%20moderates%20energy%20turnover%20is%20hampered%20by%20a%20lack%20of%20information%20regarding%20how%20relevant%20enzymes%20differ%20in%20sequence%2C%20expression%2C%20and%20regulation.%20To%20explore%20these%20questions%2C%20we%20generated%20a%20chromosome%20scale%20genome%20assembly%20of%20the%20ruby-throated%20hummingbird%20%28%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20A.%20colubris%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%29%20using%20a%20combination%20of%20long-%20and%20short-read%20sequencing%2C%20scaffolding%20it%20using%20existing%20assemblies.%20We%20then%20used%20hybrid%20long-%20and%20short-read%20RNA%20sequencing%20of%20liver%20and%20muscle%20tissue%20in%20fasted%20and%20fed%20metabolic%20states%20for%20a%20comprehensive%20transcriptome%20assembly%20and%20annotation.%20Our%20genomic%20and%20transcriptomic%20data%20found%20positive%20selection%20of%20key%20metabolic%20genes%20in%20nectivorous%20avian%20species%20and%20deletion%20of%20critical%20genes%20%28%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20SLC2A4%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%2C%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20GCK%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%29%20involved%20in%20glucostasis%20in%20other%20vertebrates.%20We%20found%20expression%20of%20a%20fructose-specific%20version%20of%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20SLC2A5%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20putatively%20in%20place%20of%20insulin-sensitive%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20SLC2A5%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%2C%20with%20predicted%20protein%20models%20suggesting%20affinity%20for%20both%20fructose%20and%20glucose.%20Alternative%20isoforms%20may%20even%20act%20to%20sequester%20fructose%20to%20preclude%20limitations%20from%20transport%20in%20metabolism.%20Finally%2C%20we%20identified%20differentially%20expressed%20genes%20from%20fasted%20and%20fed%20hummingbirds%20suggesting%20key%20pathways%20for%20the%20rapid%20metabolic%20switch%20hummingbirds%20undergo.%22%2C%22date%22%3A%222023-05-08%22%2C%22language%22%3A%22en%22%2C%22DOI%22%3A%2210.1101%5C%2Fgr.276779.122%22%2C%22ISSN%22%3A%221088-9051%22%2C%22url%22%3A%22http%3A%5C%2F%5C%2Fgenome.cshlp.org%5C%2Flookup%5C%2Fdoi%5C%2F10.1101%5C%2Fgr.276779.122%22%2C%22collections%22%3A%5B%22PUVBHFJ6%22%2C%227EZD2CLL%22%2C%225UIRG3NX%22%2C%226W7A2Q55%22%2C%22D55ZIPIZ%22%5D%2C%22dateModified%22%3A%222023-05-11T14%3A15%3A28Z%22%7D%2C%22image%22%3A%5B%22https%3A%5C%2F%5C%2Fwww.welchbiology.com%5C%2Fwp-content%5C%2Fuploads%5C%2F2023%5C%2F07%5C%2FGershman_et_al_Genome_Res_2023-150x150.jpg%22%2C150%2C150%2Ctrue%5D%7D%5D%7D
Ali, R. S., Dick, M. F., Muhammad, S., Sarver, D., Hou, L., G. William Wong and Welch, K. (2020). Glucose transporter expression and regulation following a fast in the ruby-throated hummingbird, Archilochus colubris. Journal of Experimental Biology 223, jeb229989. Download
Gershman, A., Hauck, Q., Dick, M., Jamison, J. M., Tassia, M., Agirrezabala, X., Muhammad, S., Ali, R., Workman, R. E., Valle, M., et al. (2023). Genomic insights into metabolic flux in hummingbirds. Genome Res. gr.276779.122. Download