# Primary-paper evidence: betaTub97EF

Myachina et al. (2017), Development 144:4573–4587. PMID:29084803. [DOI:10.1242/dev.156109](https://doi.org/10.1242/dev.156109).

Source: [publisher full text](https://journals.biologists.com/dev/article/144/24/4573/48236/Drosophila-Tubulin-97EF-is-upregulated-at-low), inspected 2026-09-09 UTC. This is a selected excerpt and reading note, not a complete publication cache.

## Mitotic localization

The Results section describing paralog-specific immunolabeling states:

> Specific signals, although weaker, were observed in wing imaginal discs (also in spindles during mitosis)

This supports gene-level spindle residence and is compatible with mitotic participation. It does not demonstrate an essential cell-cycle requirement or distinguish the two internal splice variants.

## Isoform scope

The Results around Figure 4 distinguish mutually exclusive internal exons 4B and 4C. The more abundant 4B transcript increases at low temperature, whereas 4C decreases. The Discussion reports differences at 13 positions within a 40-residue segment; both termini are shared. Overexpression of 4C is more detrimental than 4B. Exact accession mapping is therefore needed before assigning cold-induced expression to a selected protein isoform.

## Both splice forms retain tubulin function

The Results section on transgenic rescue states:

> UASt-βTub97EF(4B) and UASt-βTub97EF(4C) provided only limited rescue.

The resulting second-instar survival extends beyond the first-instar lethality of betaTub56D loss. This supports retained broad tubulin function in both variants, without equating their cold responses or quantitative stability.