Pronunciation: [θˈal] (IPA) 
The spelling of the word "thal" might seem tricky, but it's actually quite straightforward if you're familiar with phonetic transcription. In IPA, "thal" is spelled as /θæl/. The symbol "/" marks the beginning and end of a transcription. The sound /θ/ is often spelled "th," as in "think" or "thick." The vowel sound /æ/ is similar to the "a" in "cat" or "nap." Put together, the word "thal" sounds like "thahl" or "thall."
THAL is an acronym for the term "Thymidine Haploid Auxotroph Lethality." It refers to a scientific phenomenon observed in molecular genetics, specifically in studies involving the bacterium Escherichia coli (E. coli). In this context, THAL describes a particular mutation in the thymidine biosynthesis pathway of E. coli, leading to the inability of the bacterium to grow and survive in the absence of exogenous thymidine.
Thymidine is a nucleoside crucial for DNA synthesis, and E. coli typically can produce thymidine by itself. However, organisms harboring the THAL mutation are unable to synthesize and acquire thymidine, creating an auxotrophic dependency on receiving it from an external source. Consequently, if E. coli with the THAL mutation is cultivated in a thymidine-deficient medium, this lethal condition inhibits cell growth and results in the death of the bacterium.
THAL mutations are often employed in genetic and biochemical research as a tool to elucidate the relationship between specific genes and thymidine biosynthesis pathways, as well as to study different aspects of microbial physiology and biochemistry. This mutation can be engineered intentionally to manipulate the growth patterns and viability of E. coli strains, facilitating the investigation of the function of various genes and metabolic pathways that are closely related to thymidine production. Overall, THAL provides valuable insights into the intricate mechanisms governing thymidine metabolism and the essential role it plays in cellular survival.
