Mutant or not mutant ??

i hope the questions below will not sound silly to you ,but i really hope as if anyone could help me to clear up my mind:

excerpted from journal:

“Transgenic worms carrying a constitutively active mutation in goa-1(syIs9) (called ‘goa- 1(gf)’ here), which therefore have less neurosecretion, were more
resistant than wild-type worms to PA14 (Fig. 3a and Supplementary Tables 1 and 4)… Because a ‘phenocopy’ of the locomotory defects of goa-1 and dgk-1
can be created by treating wild-type worms with phorbol 12-myristate 13-acetate (PMA), a diacylglycerol mimic, we determined if PMA treatment also rendered worms more susceptible to PA1…Worms treated with PMA, but not those treated with its inactive analog 4-alpha-PMA, were hyperactive (Supplementary Fig. 6a online), had a shorter mean survival time on PA14…”

  1. locomotory defect of goa-1 and dgk-1

may i know what is the context about ? is it that goa-1 gene confers to the phenotype of locomotion defect or mutation in goa-1 would actually lead to defect ???

sometimes it is good that journal wil put “mutation in abc-1 gene” or “loss-of-function in gene abc-1” or “abc-1 mutants”,
but what if when they just put the gene name, abc-1 in the sentence without annotating the word mutation/loss-of-function, so what it is supposed to mean ? the gene itself or the loss of gene ?

thank you.